CEA |   |   |   |   |   |   | webmail : intra - extra |  Accès VPN-SSL | Contact | Français

PhD subjects

Dernière mise à jour : 29-03-2017

70 sujets IRAMIS

• Analytic chemistry

• Atomic and molecular physics

• Bioinformatics, bio-molecular simulation

• Biotechnologies,nanobiology

• Cellular biology, physiology and cellular imaging

• Chemistry

• Climate modelling

• Materials and applications

• Mesoscopic physics

• Molecular biophysics

• Physical chemistry and electrochemistry

• Radiation-matter interactions

• Soft matter and complex fluids

• Solid state physics, surfaces and interfaces

• Ultra-divided matter, Physical sciences for materials

 

SL-DRF-17-0549

Research field : Analytic chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Laurent MUGHERLI

Martine Mayne

Starting date : 01-10-2017

Contact :

Laurent MUGHERLI

CEA - DRF/IRAMIS/NIMBE/LEDNA

0169089427

Thesis supervisor :

Martine Mayne

CEA - DRF/IRAMIS/NIMBE/LEDNA

01 69 08 48 47

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=lmugherl

More : http://iramis.cea.fr/nimbe/ledna/

Development of a highly powerful analytical and diagnostic tool based on magnetic resonance and additive fabrication

SL-DRF-17-0421

Research field : Analytic chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM)

Saclay

Contact :

Patrick BERTHAULT

Starting date : 01-10-2017

Contact :

Patrick BERTHAULT

CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

Thesis supervisor :

Patrick BERTHAULT

CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

More : http://iramis.cea.fr/nimbe/Pisp/patrick.berthault/

More : http://iramis.cea.fr/nimbe/lsdrm/

More : http://iramis.cea.fr/Phocea/Vie_des_labos/Ast/ast.php?t=projets&id_ast=2194

In the thesis we wish to take advantage of our advances in spin-hyperpolarization and microfluidic to study by NMR processes or organisms in operation. Two research areas, one in the field of energy and the other in the field of health, will be addressed:



i) the study of the migration of different ionic species during the operation of a redox flow battery. The modularity of our patented system of mini-bubble pump will allow us to monitor by spectroscopy and imaging different isotopes in several positions of the battery. In a second step, the components and the geometry will be adapted to the organic flow cells, the main aim being to understand and analyze the degradation mechanism and products of the redox molecule (anthraquinone derivative) on the redox cycle.



ii) thanks to the microfluidic channels constructed by 3D printing, we will introduce into the core of the magnet devices that reproduce the standard conditions required for cell culture. It will therefore be possible to carry out NMR measurements making it possible to follow the time evolution of the sample over several hours in response to any stress, without disturbance of the cell metabolism due to their prior manipulation. Since we develop hyperpolarized gas probes that have the property of maintaining their polarization during the transfer of the cell membrane, we will deepen these studies with these optimized experimental setups.

Electronic dynamics of bio-relevant systems: a synergetic experimental and theoretical approach

SL-DRF-17-0172

Research field : Atomic and molecular physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

(SBM)

Saclay

Contact :

Michel MONS

Valérie BRENNER

Starting date : 01-10-2017

Contact :

Michel MONS

CEA - DRF/IRAMIS/LIDyL/SBM

01 69 08 20 01

Thesis supervisor :

Valérie BRENNER

CEA - DRF/IRAMIS/LIDyL/SBM

01.69.08.37.88

More : http://iramis.cea.fr/Pisp/valerie.brenner/

More : http://iramis.cea.fr/LIDyL/SBM/

More : http://iramis.cea.fr/Pisp/michel.mons/

Many complex molecular systems absorbing light in the near UV spectral range, including those of paramount biological importance, like DNA bases or proteins, are endowed with mechanisms of excited-state deactivation following UV absorption. These mechanisms are of major importance for the photochemical stability of these species since they provide them a rapid and efficient way to dissipate the electronic energy in excess into vibrations, thus avoiding photochemical processes to take place and then structural damages which affect the biological function of the system. In this context, the study of gas phase bio-relevant systems such peptides as proteins building blocks should lead to a better understanding of the photophysical phenomena involved in the relaxation mechanisms of life components. This Ph. D project aims at both investigating the electronic dynamics of bio-relevant model systems, i.e. building block of life components, and documenting the basic phenomena controlling the lifetime of the excited states, through a dual approach using most recent methodological tools, consisting of:

i) An experimental characterization of i) the lifetimes, in nano-, pico- and femtosecond pump-probe experiments, and ii) the nature of the electronic states formed. Sophisticated diagnostic techniques, such as a photo-electron velocity map imaging diagnosis, will be used. These experiments will allow us to identify the relaxation pathways followed by the system, and in particular to assess the role of the several excited states together with the effect of its environment.

ii) A theoretical modeling of the processes involved, in particular to assess the role of specific regions of the potential energy surface (PES), namely the conical intersections, and to determine the motions that trigger deactivation. The systems’ size, their flexibility, the non-covalent interactions, which govern the structures, and the nature of the excited states require the implementation of a computational strategy using sophisticated quantum chemical methods dedicated to excited states (non-adiabatic dynamic, coupled cluster method and multireference configuration interaction method) in order to characterize the first excited states, simulate their PES and eventually determine the relaxation pathways.

Moreover, this work will take place in the context of the ANR project, ESBODYR, for «Excited States of BiO-relevant systems: towards ultrafast conformational Dynamics with Resolution» (Coord V. Brenner, 2014-2017)

Laser-induced electron diffraction: Increase of the re-scattering energy

SL-DRF-17-0532

Research field : Atomic and molecular physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Christian CORNAGGIA

Starting date : 01-10-2017

Contact :

Christian CORNAGGIA

CEA - DRF/IRAMIS/LIDYL/ATTO

+33 1 69 08 43 65

Thesis supervisor :

Christian CORNAGGIA

CEA - DRF/IRAMIS/LIDYL/ATTO

+33 1 69 08 43 65

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ccor

More : http://iramis.cea.fr/LIDyL/

More : http://attolab.fr/

The thesis proposal is aimed at the development of a new ultrafast molecular imaging technique in the gas phase based on the last advances of Atomic Physics in strong laser fields. The analysis of the rescattering dynamics of the photoelectron onto the ionic core will allow us to measure the molecular parameters with a temporal resolution down to a few hundreds of attoseconds. Until now, we have extracted the elastic differential cross sections for simple molecules with collision energies of a few tens of electron-volts, using laser pulses from 10 to 40 femtoseconds at 0.8 µm in the intensity range 10^{13}-10^{14} W/cm^2. The low collision energies make the cross sections calculations very demanding for the extraction of the molecular geometry, and inhibit us from using the independent atom models used in conventional electron diffraction. Our goals are to check the validity of these models in the case of rescattering, and to test them while the collision energy will be increased. For this last point, three experimental strategies are planned: The increase of the laser intensity with pulse durations below 10 femtoseconds, the increase of the wavelength in the mid-infrared range to 1.6 µm and 3.2 µm, and finally a new diffraction scheme where a low-energy photoelectron in injected in the continuum with a first femtosecond pulse at 800 nm or an attosecond pulse in the EUV, and is then accelerated to a high energy with a second pulse in the mid-infrared at 3.2 µm. This proposal involves theoretical and experimental developments which require a pronounced inclination for Atomic and Molecular Physics, ultrafast laser technologies, numerical analysis, and experimentation. The experiments take place in Saclay at 0.8 µm and in Palaiseau for the mid-infrared. The theoretical developments are done done in collaboration with Laboratoire des Solides Irradiés at Palaiseau and Institut des Sciences Moléculaires at Orsay.

Electronic dynamics of bio-relevant systems: toward a modeling of the deactivation processes of excited states

SL-DRF-17-0174

Research field : Atomic and molecular physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

(SBM)

Saclay

Contact :

Valérie BRENNER

Starting date : 01-10-2017

Contact :

Valérie BRENNER

CEA - DRF/IRAMIS/LIDyL/SBM

01.69.08.37.88

Thesis supervisor :

Valérie BRENNER

CEA - DRF/IRAMIS/LIDyL/SBM

01.69.08.37.88

More : http://iramis.cea.fr/Pisp/valerie.brenner/

More : http://iramis.cea.fr/LIDyL/SBM/

Many complex molecular systems absorbing light in the near UV spectral range, including those of paramount biological importance, like DNA bases or proteins, are endowed with mechanisms of excited-state deactivation following UV absorption. These mechanisms are of major importance for the photochemical stability of these species since they provide them a rapid and efficient way to dissipate the electronic energy in excess into vibration, thus avoiding photochemical processes to take place and then structural damages which affect the biological function of the system. In this context, the study of gas phase bio-relevant systems such peptides as proteins building blocks should lead to better understanding the photophysical phenomena involved in the relaxation mechanisms of life components. The size of the systems, their flexibility, the existence of non-covalent interactions which governs structures and the nature of the excited states require the use of sophisticated theoretical models in order to characterize the preferentially formed conformations in gas phase as well as to investigate the electronic relaxation mechanisms of the first excited states. The focus of the PhD project concerns the implementation of a computational strategy to both characterize the first excited states and simulate their potential energy surfaces in order to determine the relaxation pathways. This theoretical research project contains then the development, evaluation and validation of modern quantum chemical methods dedicated to excited states. It will be backed up by key gas phase experiments performed in our group on flexible molecules using recent spectroscopic techniques which provide precise data on the spectroscopic properties and electronic dynamic of relaxation. Moreover, it will take place in the context of one ANR project, ESBODYR or "Excited States of BiO-relevant systems: towards ultrafast conformational Dynamics with Resolution", (Coord V. Brenner, 2014-2017).

Spectroscopy and dynamics of porphyrin molecular assemblies

SL-DRF-17-0462

Research field : Atomic and molecular physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

(DYR)

Saclay

Contact :

Lionel POISSON

Starting date : 01-10-2016

Contact :

Lionel POISSON

CNRS-UMR9222 - DSM/IRAMIS/LIDYL/DYR

01 69 08 51 61

Thesis supervisor :

Lionel POISSON

CNRS-UMR9222 - DSM/IRAMIS/LIDYL/DYR

01 69 08 51 61

More : http://iramis.cea.fr/Pisp/lionel.poisson/

More : http://iramis.cea.fr/LIDYL/DyR/

This thesis is a fundamental approach designed to better understand the interactions in hybrid molecular systems combining metals and organic molecules. Its aim is to understand and model the structure and dynamics of the formation of these molecular complex, as well as dynamics of their electronic relaxation. An efficient way to produce and study model organometallic structures is to use thin droplets of superfluid helium as a chemical nano-reactor.



In practice, during this PhD, one of the components will be a porphyrin in order to address problems related to photovoltaics. IR spectroscopy of molecular assemblies hosted in helium droplets will be the tool of choice to provide information on the structural aspects. The dynamics of the electronic relaxation following an excitation will also be addressed during this thesis. It is the time-resolved electronic spectroscopy, carried out on ATTOLab, which will be used to inform on the corresponding dynamics. It should be noted that the experimental GOUTTELIUM device on which the spectroscopic part of this thesis will be conducted is unique in France.

Molecular modeling of reversible functional amyloid formation

SL-DRF-17-0506

Research field : Bioinformatics, bio-molecular simulation
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Frédéric GOBEAUX

Stéphane ABEL

Starting date : 01-10-2017

Contact :

Frédéric GOBEAUX

CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 24 74

Thesis supervisor :

Stéphane ABEL

CEA - DRF/IBITEC-S/SB²SM/LBMS

01 69 08 75 92

More : http://iramis.cea.fr/Pisp/frederic.gobeaux/

More : http://ibitecs.cea.fr/drf/ibitecs/Pages/services/sb2sm/lbms/modelisation-moleculaire-proteines-membranaires.aspx

More : http://st-abel.com/

Our group studies assembly mechanisms of functional amyloids formed by peptide hormones and their synthetic analogues. Contrary to pathological amyloid fibrils, these « functional » fibrils are able to disassemble under the effect of physical-chemical stimuli. In vivo, these fibrils serve to store hormones in dense vesicles before they are released.



In the frame of this project, we aim at complement experimental studies (electron microscopy, spectroscopies and x-ray scattering) by molecular dynamic (MD) simulations in order to better understand the formation of experimentally observed structures but also of early aggregates and assembly mechanisms. We will seek to model the conformations of the peptides as a function of their state of charge, map out free energy path leading to the formation of intermediary species and determine the specific role of différent interactions at play.



The simulation work will be performed in constant interaction with experimental studies carried out in parallel.

Printed Versatile Drug Nanocarriers for Personalized Medicine - Printdrugs

SL-DRF-17-0446

Research field : Biotechnologies,nanobiology
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Thomas BERTHELOT

Starting date : 01-10-2017

Contact :

Thomas BERTHELOT

CEA - DRF/IRAMIS/NIMBE/LICSEN

01.69.08.65.88

Thesis supervisor :

Thomas BERTHELOT

CEA - DRF/IRAMIS/NIMBE/LICSEN

01.69.08.65.88

More : http://iramis.cea.fr/Pisp/thomas.berthelot/

More : http://iramis.cea.fr/nimbe/licsen/

The application of nanotechnologies in medicine, named nanomedicine, offers numerous possibilities in healthcare. In the fields of antibiotherapy, is the difficulty to eradicate intracellular infections mainly due to the poor intracellular penetration of commonly used antibiotics. New strategies as nanocarriers loaded with antibiotics represent a promising approach to eradicate Bacteria intracellular infections. Currently, polymer nanoparticles are obtained by preformed polymers or by direct polymerization of monomers using classical polymerization combined with microfluidics. These devices are usually fabricated by conventional clean room techniques involving specialized resources and skills. Their developments are cost and time expensive but also limit nanoparticle fabrication to academic research. The aim of this multidisciplinary, innovative and ambitious Thesis project is to use printing technologies to “print” functional drug nanocarriers and use the pL droplets generated as very small reactors. To validate one of the multiple applications derived from the project, the printed drug nanocarriers will be loaded with antibiotics and used to treat intracellular bacterial infections. Moreover, different nanoparticle printer prototypes will be created in connection with the development of the “printed” process for nanoparticle synthesis.

Co-printing organs and sensors: the instrumented organ as a tool for understanding evolution of 3D printed tissue - BioNIC

SL-DRF-17-0449

Research field : Cellular biology, physiology and cellular imaging
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Thomas BERTHELOT

Starting date : 01-10-2017

Contact :

Thomas BERTHELOT

CEA - DRF/IRAMIS/NIMBE/LICSEN

01.69.08.65.88

Thesis supervisor :

Thomas BERTHELOT

CEA - DRF/IRAMIS/NIMBE/LICSEN

01.69.08.65.88

More : http://iramis.cea.fr/Pisp/thomas.berthelot/

More : http://iramis.cea.fr/nimbe/licsen/

Regenerative medicine, and in particular the 3-D printing of organ holds the promise to revolutionize healthcare. Today however, it remains difficult to study how 3-D constructs of cells evolve with time. Indeed, most techniques, such as optical microscopy, cannot probe these complex assemblies of cells. We propose a novel approach to the monitoring of 3-D cell construct by relying on the co-printing a network of sensors. Theses sensors, based on novel biocompatible electrically conductive inks will make it possible to embed wires and sensors deep within the organ thus allowing the study of key parameters throughout its volume as a function of time. This will produce valuable data to better understand how such organs age or react to drugs. Eventually, one could imagine that printed organs used in a clinical setting will also be instrumented to allow the patient to better monitor his recovery. ?

Functional Rotaxanes for Light Harvesting and Photovoltaics

SL-DRF-17-0410

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Stéphane CAMPIDELLI

Jean WEISS

Starting date : 01-10-2017

Contact :

Stéphane CAMPIDELLI

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Thesis supervisor :

Jean WEISS

CNRS - Chimie des Ligands à Architecture Contrôlée (CLAC) Institut de Chimie de Strasbourg - UMR7177

03 68 85 14 23

More : http://iramis.cea.fr/Pisp/stephane.campidelli/

More : http://iramis.cea.fr/nimbe/licsen/

This project takes advantage of a new synthetic approach of rotaxane structures which is currently developed at the “Chimie des Ligands à Architecture Contrôlée (CLAC)” of the University of Strasbourg and is based on the expertise of the “Laboratoire d’Innovation en Chimie des Surfaces et Nanosciences (LICSEN)” of the CEA-Saclay in the functionalization of carbon-based nanomaterials.

The project targets photonic dyads and triads with a rotaxane structure and the extension of the synthetic approach to multichromophoric assemblies attached to carbon nanotubes as electron collectors. The project is fundamental and should unravel new concepts in the design of photoactive material using non-covalent molecular scaffolds all available in gram scale.

The PhD project will be achieved in collaboration between the University of Strasbourg and CEA-Saclay. For this project, a formation of organic chemist is required (Master 2 in Organic synthesis or equivalent).

synthesis by laser pyrolysis of photocatalysts efficient to obtion alcene compounds

SL-DRF-17-0838

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Nathalie Herlin

Starting date : 01-10-2017

Contact :

Nathalie Herlin

CEA - DRF/IRAMIS/NIMBE/LEDNA

0169083684

Thesis supervisor :

Nathalie Herlin

CEA - DRF/IRAMIS/NIMBE/LEDNA

0169083684

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=herlin

More : http://iramis.cea.fr/nimbe/ledna/

Bacteriostatic polymer films

SL-DRF-17-0693

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Geraldine CARROT

Marie-Noelle BELLON-FONTAINE

Starting date : 01-10-2017

Contact :

Geraldine CARROT

CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 21 49

Thesis supervisor :

Marie-Noelle BELLON-FONTAINE

AgroParisTech - MICALIS/ INRA/ AgroParisTech

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=carrot

More : http://iramis.cea.fr/nimbe/licsen/

Microbial multiplication is one of the most serious concerns for many commercial applications, particularly food packaging where the product deterioration is closely linked to both economic and environmental concerns (decrease of food waste by increasing the DLC, limit date of consumption). In this particular domain, the challenge is double: 1-to limit the growth of the total flora (to prevent the multiplication responsible for alteration), and 2-to preserve a certain amount of endogenous bacteria useful for an appropriate maturation of the fresh food product. The expected effect is therefore more bacteriostatic than fully antibacterial. We need materials that are both contact-active and biocide. In this context, stable cationic polymers are particularly interesting (low MCI in solution, Minimum Concentration for Inhibition) and the challenge here will be to develop a robust and efficient method to graft them onto various substrates such as glass, stainless steel and particularly polyolefins that are widely used in food packaging. This thesis project involves two academic Labs: CEA/NIMBE-LICSEN, expert in surface chemistry and AgroParisTech/INRA-MICALIS specialized in the study of bio-adhesion and biofilms. Industrial partners are also involved in this project.

Realization of efficient and innovative functionalization of graphene and carbon nanotubes for energy and material science

SL-DRF-17-0042

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Stéphane CAMPIDELLI

Starting date : 01-10-2017

Contact :

Stéphane CAMPIDELLI

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

Thesis supervisor :

Stéphane CAMPIDELLI

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

More : http://iramis.cea.fr/Pisp/stephane.campidelli/

More : http://iramis.cea.fr/nimbe/licsen/

The aim of this project is the development of new functional carbon nanotubes and graphene derivatives. So far, functionalization of carbon-based nano-objects is based either on the covalent grafting or on the non-covalent adsorption of molecules on the nanotube/graphene surfaces. It is well established that the covalent grafting of molecules give rise to robust conjugates since the nano-objects and the addends are linked through covalent bonds; however, the transformation of carbon atoms hybridized sp2 into sp3 in the nanotube framework induces a sizeable loss of their electronic properties. On the contrary, the non-covalent functionalization permits to better preserve the electronic properties of the nanotubes. So, for a number of applications, the non-covalent functionalization should be preferred. However, this approach suffers from a major drawback which is the lack of stability of the resulting assemblies. Indeed, molecules adsorbed onto the nanotube sidewall can desorb, more or less easily, when for example the solvent changes or the nanotubes are filtered and redispersed.

Recently we developed a method combining most advantages of these two techniques without their major drawbacks. From the applicative point of view, this method can be used to create new carbon-based nanomaterials for photovoltaic, catalytic and electronic applications.

Solid catalysts for the hydrogenation of the CO bonds in CO2, amides and esters

SL-DRF-17-0558

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (LCMCE)

Saclay

Contact :

Caroline GENRE

Thibault Cantat

Starting date : 01-10-2017

Contact :

Caroline GENRE

CEA - DRF/IRAMIS/NIMBE/LCMCE

0169085879

Thesis supervisor :

Thibault Cantat

CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=cgenre

More : http://iramis.cea.fr/Pisp/thibault.cantat/index_fichiers/cantat.html

Over 85% of the world energy production comes from fossil fuels, and over 95% of materials based on organic chemicals (plastics, fertilizers, textiles…) are synthesized through petrochemistry. In a context of dwindling oil resources and a renewed effort against CO2 production, our team has developed efficient catalysts for a dozen of processes that allow synthesizing methanol, methylamines, aromatic derivatives and other chemicals directly from CO2 recycling. This doctoral project aims at discovering innovative solid catalysts for transformation such as CO2 hydrogenation and most of all amide and ester hydrogenation. These compounds indeed are difficult to reduce and the few existing catalytic processes use noble metals and/or very harsh operating conditions. Building on promising results obtained in our group, the study’s goal will be to synthesize noble-metal free solid catalysts with excellent reactivity even in soft conditions, to test the potentialities of other reductants, like formic acid, in the hydrogenation process, and to understand in detail what parameters influence the activity at the catalytic interface in those systems.

Functionalized carbon nanotubes for Lithium-Sulphur and Lithium-Organic batteries

SL-DRF-17-0039

Research field : Chemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Céline BARCHASZ

Stéphane CAMPIDELLI

Starting date : 01-10-2017

Contact :

Céline BARCHASZ

CEA - DRT/DEHT//LGI

04 38 78 90 36

Thesis supervisor :

Stéphane CAMPIDELLI

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-51-34

More : http://iramis.cea.fr/Pisp/stephane.campidelli/

More : http://iramis.cea.fr/nimbe/licsen/

During this PhD, we will study the interest of carbon-based nanomaterials as positive electrode for Lithium/Sulphur and Lithium/Organic accumulators. To this end, we will functionalize carbon nanotubes and graphene with molecules containing electroactive functional groups and we will test these materials in coin cells. This project is realized in collaboration between 2 laboratories of the fundamental science and technological research divisions in CEA-Saclay and CEA-Grenoble.

Improving stochastic generators of climate/financial data using the underlying dynamics

SL-DRF-17-0773

Research field : Climate modelling
Location :

Service de Physique de l'Etat Condensé (SPEC)

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX)

Saclay

Contact :

Davide Faranda

Bérengère DUBRULLE

Starting date : 01-09-2017

Contact :

Davide Faranda

CEA - DRF/LSCE (DSM)

0169085232

Thesis supervisor :

Bérengère DUBRULLE

CNRS - DRF/IRAMIS/SPEC/SPHYNX

0169087247

More : http://iramis.cea.fr/spec/Phocea/Membres/Annuaire/index.php?uid=dfaranda

More : http://iramis.cea.fr/spec/sphynx/

More : http://iramis.cea.fr/Pisp/berengere.dubrulle/index.html

Forecasting and understanding the behavior of complex systems such as turbulence, climate and finance is a challenging task. To tackle this problem, various tools have been developed using dynamical systems theory, statistical mechanics or stochastic fits to the data using e.g. Auto Regressive Moving Average (ARMA) processes. Such approaches are however limited by the presence of multiple metastable states, that can trap the system in non-equilibrium quasi-steady state, or attract the trajectories in the phase space.



Examples of such meta-stable states are blocked and zonal flows in the mid-latitude atmospheric dynamics, crises and period of growth in economy and finance. At present time, there is no general theory that allows the prediction of the plausibility of, time-life of or dynamics around such meta-stable states. Improved description of the system dynamics of the trajectories in the presence of metastable states have been recently obtained by splitting the original time-series in short subsamples that obey basic ARMA processes [1,2,3]. In those papers, several indicators have been derived to analyze the data. They provide information about the number of degrees of freedom active in the systems and the probability of jumps towards other metastable states.

The goal of this PhD study is to go one step further, and use this method to forecast the behavior of complex systems. The PhD candidate will construct stochastic generators of plausible turbulent, climate and financial fields by including the underlying dynamical properties as derived by the previous indicators. She/he will assess the quality of the generated fields by comparing the results on real data. During the PhD thesis, the candidate will acquire competences in statistics, fundamental physics, climate dynamics and finance. She/he will develop numerical tools and models with the analysis of time-series.

The Phd Thesis require a good knowledge of stochastic processes and therefore a background on applied statistics or theoretical physics. The candidate should know how to use statistical analysis software as R, Matlab and/or Python. She/he should have a good level of understanding of English language, to work in an international environment.



[1] Davide Faranda, Gabriele Messori and Pascal Yiou. Dynamical proxies of North Atlantic predictability and extremes. Accepted for publication in Scientific Reports, 2017.

[2] Guillaume Nevo, Nikki Vercauteren, Amandine Kaiser, Berengere Dubrulle, Davide Faranda. A statistical-mechanical approach to study the hydrodynamic stability of stably stratified atmospheric boundary layer. Submitted, 2017.

[3] Davide Faranda and Dimitri Defrance: A wavelet-based-approach to detect climate change on the coherent and turbulent component of the atmospheric circulation. Earth System Dynamics, 7 517-523, 2016.

All optical detection of greenhouse or hazardous gases

SL-DRF-17-0480

Research field : Materials and applications
Location :

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Saclay

Contact :

Alain BRAUD

Starting date : 01-10-2017

Contact :

Alain BRAUD

CEA - DRF/IRAMIS/CIMAP/CIMAP

02.31.45.25.60

Thesis supervisor :

Alain BRAUD

CEA - DRF/IRAMIS/CIMAP/CIMAP

02.31.45.25.60

More : http://cimap.ensicaen.fr/spip.php?article198

More : http://cimap.ensicaen.fr/spip.php?rubrique71

More : http://cimap.ensicaen.fr/

The aim of this PhD is to develop an original technology for the all-optical detection of greenhouse gases or hazardous gases (CH4, CO, sarin gas and others) based on rare earth-doped materials. This work is connected with the OPTIGAS ANR project (2016-2019) led by the MIL group of CIMAP and on the other hand with NASA (NASA Langley Research Center, USA). The detection is based on gas absorption in the Mid-infrared (IR) region (3-5µm) and even more selectively, in the LWIR (8-12µm). The aim of the PhD is to develop specific infrared sources, but also to implement an original energy conversion from IR photons to the visible domain in order to carry the detection signal over long distances using silica fibers. This PhD work will therefore aim to validate the relevance of the materials as infrared emitters and as frequency converters. The PhD will include a modeling part of the excitation and emission mechanisms of these luminescent materials and another experimental part that will include various optical spectroscopy experiments (absorption, emission, time-resolved emission and excitation spectroscopy, excited state absorption spectroscopy and so on...) and finally the demonstration of an all-optical detection for several gases.

Quantum Phase Slips in NanoWires

SL-DRF-17-0430

Research field : Mesoscopic physics
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Quantronique (GQ)

Saclay

Contact :

Philippe JOYEZ

Starting date : 01-09-2016

Contact :

Philippe JOYEZ

CEA - DRF/IRAMIS/SPEC/GQ

0169087444

Thesis supervisor :

Philippe JOYEZ

CEA - DRF/IRAMIS/SPEC/GQ

0169087444

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=pj

More : http://iramis.cea.fr/spec/Pres/Quantro/static/

The celebrated Josephson junction is so far the only known non-linear non-dissipative electronic component. These key properties place it at the heart of essentially all superconducting electronic devices: SQUIDS magnetometers, Josephson Volt standards but also the recently developed quantum information processing circuits or quantum-limited amplifier circuits.

The present thesis aims at testing the practical feasibility and actual properties of a second non-linear non-dissipative superconducting component which was proposed by Mooij and Nazarov [1] nearly a decade ago. This new component is called a Quantum Phase Slip Junction (QPSJ). It consists of a very thin superconducting wire which is predicted to behave as the exact quantum dual of the Josephson junction. Such duality means that the equations describing the QPSJ and the Josephson junction are formally identical save for charge and phase exchanging roles. In other words, where a Josephson junction coherently superposes many states differing by the number of Cooper pairs having tunneled through the barrier, a QPSJ coherently superposes many states differing by the number of 2p phase windings along the wire, which can be seen as a superposition of various number of flux quanta having tunneled across the wire. Would such a QPSJ component become actually available, it would be a genuine breakthrough. In particular, it should enable the realization of an experiment dual to the celebrated AC Josephson effect that would be emblematic of QPSJ physics: Instead of establishing a metrological link between the Volt and the second, this dual experiment would link the Ampere to the second. Likewise, a whole new range of high impedance superconducting circuits (which are presently downright antinomic) would become feasible. This would unquestionably open up a new era for the whole field of superconducting circuits.

Since the proposal of QPSJ came to light, a handful of experiments have investigated the physics of QPSJ, partially confirming the predictions [2,3], but raising more questions than they brought answers. In particular the very basic prediction of a periodic charge modulation in QPSJs is lacking a clear-cut confirmation [4]. The main goal of this thesis is to perform the experiment proposed by Hriscu and Nazarov [5], aiming specifically at testing this charge modulation.



[1] Mooij and Nazarov, Nat. Phys. 2, 169 (2006).

[2] Astafiev et al., Nature 484, 355 (2012),

[3] Peltonen et al. Phys. Rev. B 88, 220506(R) (2013)

[4] Hongisto and Zorin, Phys. Rev. Lett. 108, 097001 (2012)

[5] Hriscu and Nazarov, Phys. Rev. Lett. 106, 077004 (2011)

Electronic Mach Zehnder in graphene

SL-DRF-17-0036

Research field : Mesoscopic physics
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Nano-Electronique (GNE)

Saclay

Contact :

Preden Roulleau

Christian Glattli

Starting date : 01-10-2017

Contact :

Preden Roulleau

CEA - DRF/IRAMIS/SPEC/GNE

0169087311

Thesis supervisor :

Christian Glattli

CEA - DRF/IRAMIS/SPEC/GNE

0607060501

More : http://iramis.cea.fr/Pisp/preden.roulleau/

More : http://nanoelectronics.wikidot.com/

More : http://iramis.cea.fr/spec/index.php

Quantum computing is based on the manipulation of quantum bits (qubits) to enhance the efficiency of information processing. In solid-state systems, two approaches have been explored:

• static qubits, coupled to quantum buses used for manipulation and information transmission,

• flying qubits which are mobile qubits propagating in quantum circuits for further manipulation.



Flying qubits research led to the recent emergence of the field of electron quantum optics, where electrons play the role of photons in quantum optic like experiments. This has recently led to the development of electronic quantum interferometry as well as single electron sources. As of yet, such experiments have only been successfully implemented in semi-conductor heterostructures cooled at extremely low temperatures. Realizing electron quantum optics experiments in graphene, an inexpensive material showing a high degree of quantum coherence even at moderately low temperatures, would be a strong evidence that quantum computing in graphene is within reach.

One of the most elementary building blocks necessary to perform electron quantum optics experiments is the electron beam splitter, which is the electronic analog of a beam splitter for light. However, the usual scheme for electron beam splitters in semi-conductor heterostructures is not available in graphene because of its gapless band structure. I propose a breakthrough in this direction where pn junction plays the role of electron beam splitter [1]. Based on this, an electronic Mach Zehnder interferometer will be studied to understand the quantum coherence properties of graphene. This PhD proposal is part of the ERC starting grant COHEGRAPH (2016).





[1] Shot noise generated by graphene p-n junctions in the quantum Hall effect regime N. Kumada, F. D. Parmentier, H. Hibino, D. C. Glattli, and P. Roulleau , Nature Communications

Out-of-equilibrium thermoelectric transport in quantum conductors

SL-DRF-17-0097

Research field : Mesoscopic physics
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Mésocopie Modélisation et Thermoélectricité (GMT)

Saclay

Contact :

Geneviève FLEURY

Jean-Louis PICHARD

Starting date : 01-10-2017

Contact :

Geneviève FLEURY

CEA - DRF/IRAMIS/SPEC/GMT

0169087347

Thesis supervisor :

Jean-Louis PICHARD

CEA - DRF/IRAMIS/SPEC/GMT

0169087236

More : http://iramis.cea.fr/spec/Pisp/genevieve.fleury/

More : http://iramis.cea.fr/spec/GMT/

Seebeck and Peltier thermoelectric effects provide an eco-friendly way of converting heat into electricity and vice-versa. Thus it is possible with the Seebeck effect to harvest waste heat for producing electricity. Conversely, the Peltier effect enables local cooling of a device by investing electrical power. For a long time, thermoelectric conversion has been limited by a poor efficiency and therefore, practical applications have till date remained rare. Interest in the field has been recently rekindled by the discovery of new promising materials, by progress in nanostructuration, and by the growing societal concern about energy issues.

The purpose of this theoretical PhD thesis is to study analytically and numerically thermoelectric conversion in low-dimensional mesoscopic systems. We will consider the regime far from equilibrium where important thermoelectric effects are expected. In particular, we will investigate systems under dynamic time-dependent forcing. From a methodological standpoint, we will use the numerical tools and the analytical formalism developed at CEA-Grenoble (X. Waintal's team) for the study of (out-of-equilibrium) time-resolved quantum transport (see https://kwant-project.org/). We will adapt it to the case of thermoelectric transport and apply it to various systems (quantum dots, quantum point contacts, nanowires…).

Manipulation of the quantum state of individual superconducting excitations in nanowires

SL-DRF-17-0427

Research field : Mesoscopic physics
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Quantronique (GQ)

Saclay

Contact :

Marcelo GOFFMAN

Starting date : 01-09-2017

Contact :

Marcelo GOFFMAN

CEA - DRF/IRAMIS/SPEC/GQ

0169085529

Thesis supervisor :

Marcelo GOFFMAN

CEA - DRF/IRAMIS/SPEC/GQ

0169085529

More : http://iramis.cea.fr/Pisp/marcelo.goffman/

More : http://iramis.cea.fr/spec/Pres/Quantro/static/index.html

Electrons in superconductors form Cooper pairs that cannot be probed individually because they are delocalized and overlapping. However, localized states appear at weak links between superconducting electrodes. Using atomic contacts as a weak link, we performed the spectroscopy of these localized states [1] and demonstrated the quantum manipulation of a localized Cooper pair [2].

During the internship, we plan to develop similar experiments with InAs semiconducting nanowires. Longer coherence times are expected, and, because of the strong spin-orbit coupling in InAs, one should also be able to manipulate the spin of localized electrons.



The student will be integrated in an active research group on quantum electronics and get acquainted with advanced concepts of quantum mechanics and superconductivity. He/she will also learn several experimental techniques: low temperatures, low-noise and microwave measurements, and nanofabrication.



[1] L. Bretheau et al., “Exciting Andreev pairs in a superconducting atomic contact”

Nature 499, 312 (2013). arXiv:1305.4091

[2] C. Janvier et al., “Coherent manipulation of Andreev states in superconducting atomic contacts”

Science 349, 1199 (2015), arXiv:1509.03961

Single electron detection for electron quantum optics and electron flying qubits

SL-DRF-17-0107

Research field : Mesoscopic physics
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Nano-Electronique (GNE)

Saclay

Contact :

Christian Glattli

Starting date : 01-10-2017

Contact :

Christian Glattli

CEA - DRF/IRAMIS/SPEC/GNE

0607060501

Thesis supervisor :

-

More : http://iramis.cea.fr/Pisp/24/christian.glattli.html

More : http://nanoelectronics.wikidot.com/general

Our goal is to realize basic quantum operations using the information coded by the presence or not of a single electron (a flying qubit) propagating in a quantum conductor. This requires single electron sources to initialize the flying qubit, quantum gates in the form of electron interferometers to perform quantum operation, and single charge detectors for single shot readout. In this “electron quantum optics” approach, single electron sources, the electronic analog of single Photons sources, are already available where single electrons are created in the form of levitons. Present ballistic conductors used can also routinely provide quantum gates in the form of electron beam splitters and electron interferometers. The present Ph-D project is to realize the missing brick: the single electron detector which would allow for a full single shot quantum operation. Bolometric or charge detection schemes will be explored.

Understanding DNA condensation induced by bacterial Amyloids

SL-DRF-17-0657

Research field : Molecular biophysics
Location :

Laboratoire Léon Brillouin (LLB)

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Véronique ARLUISON

Starting date : 01-10-2017

Contact :

Véronique ARLUISON

Université Paris VII - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Thesis supervisor :

Véronique ARLUISON

Université Paris VII - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

More : http://iramis.cea.fr/llb/Phocea/Membres/Annuaire/index.php?uid=varluiso

More : http://www-llb.cea.fr/

Expected breakthroughs of the PhD project are to develop and to couple innovative methods for the investigation of biological self-assembled nucleoprotein nanostructures. Fluorescence microscopy imaging of these nanostructures confined in micro and nanofluidic devices, microcalorimetry, single-molecule manipulation with magnetic tweezers, small angle x-ray/neutron scattering, atomic force microscopy and infrared nanospectroscopy will be applied in order to establish the effect of a protein associated with bacterial nucleoid called Hfq. Hfq is a key protein involved in many regulatory circuits and in particular in the control of bacterial virulence. These technologies will allow following the morphology of the complexes at the nanoscale, as well as subtle changes in protein and DNA conformation such as sugar re-puckering. In particular, the PhD project will try to evaluate how Hfq amyloid region helps to form a nucleoprotein complex in order to compact DNA into a condensed form. The expected benefits for this PhD project will be twice: the development of innovative methods for the analysis of biological self-assembled nanostructures, but also new opportunities for the development of antibiotics.

Catalysts based on carbon nanotubes for Lithium-Air batteries

SL-DRF-17-0545

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Bruno Jousselme

Starting date : 01-10-2017

Contact :

Bruno Jousselme

CEA - DRF/IRAMIS/NIMBE/LICSEN

0169089191

Thesis supervisor :

Bruno Jousselme

CEA - DRF/IRAMIS/NIMBE/LICSEN

0169089191

More : http://iramis.cea.fr/Pisp/bruno.jousselme/

More : http://iramis.cea.fr/nimbe/licsen/

Society’s need for mobile energy storage (electric vehicles) will far exceed that addressed by lithium-ion batteries. As a result, there is an intense interest in possible alternatives. The lithium-air (Li-O2) battery, whether based on aqueous or non-aqueous electrolytes, is one of such alternative. It possesses a theoretical specific energy significantly greater than Li-ion batteries, and therefore could transform energy storage. However, today many challenges limit the realization of rechargeable Li-O2 battery with competitive performances. In this general context, the Ph.D. project concerns the study at the fundamental level of the use of functionalized Carbon Nanotubes as catalyst for the Oxygen Reduction Reaction in organic media and their insertion in Li-Air Batteries. The understanding of the full electrochemical/chemical reactions that occur at the surface and in the volume of the cathode materials during repeated charging and discharging will be deeply investigated to develop the rational design of improved cathodes and synthesize new materials.

Investigating of Na-oxygen batteries using in situ solid-state NMR spectroscopy

SL-DRF-17-0491

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM)

Saclay

Contact :

Alan WONG

Thibault CHARPENTIER

Starting date : 01-10-2017

Contact :

Alan WONG

CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 41 05

Thesis supervisor :

Thibault CHARPENTIER

CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

More : https://sites.google.com/site/alanwongnmr/home

More : http://iramis.cea.fr/nimbe/lsdrm/

More : http://iramis.cea.fr/nimbe/Pisp/magali.gauthier/

Rechargeable metal-O2 batteries have attracted much attention in recent years as a possible alternative to the widely used lithium-ion batteries. Particularly for sodium-oxygen batteries (Na-O2), this is due to their potential high energy density, low polarization, and more importantly low-cost and eco-friendly aspect of sodium. However, great challenges remain in the development of Na-O2 batteries and in the understanding of the underlying mechanisms taking placed inside Na-O2 batteries. Clear identifications of the discharge electrochemical pathways and their products (NaO2 or Na2O2), as well as the reactivity of the electrolyte, are crucial. The thesis objective is to investigate the electrochemical and chemical reactions in Na-O2 batteries under real-time potential cycling using recently emerged in situ solid-state NMR spectroscopy. The thesis will consist of (1) establishing an unprecedented in situ solid-state NMR facility at LSDRM for studying Na-O2 batteries; (2) understanding reaction mechanisms in Na-O2 systems; and (3) exploring new routes for improving the battery performances.

High capacity and innovative magnesium-ion batteries based on nanostructured negative electrodes

SL-DRF-17-0902

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire d'étude des éléments légers (LEEL)

Saclay

Contact :

Magali GAUTHIER

Hicham KHODJA

Starting date : 01-01-2017

Contact :

Magali GAUTHIER

CEA - DRF/IRAMIS/NIMBE/LEEL

0169084530

Thesis supervisor :

Hicham KHODJA

CEA - DRF/IRAMIS/NIMBE/LEEL

01 69 08 28 95

More : http://iramis.cea.fr/Pisp/magali.gauthier/

More : http://iramis.cea.fr/nimbe/leel/

The thesis will deal with the exploration of an innovative concept for energy storage: magnesium (Mg)-ion batteries. Magnesium appears as a great alternative to lithium due to its high capacity, low cost, abundance on Earth and largely smaller reactivity and better safety compared to lithium. However, conventional electrolytes used in Li batteries strongly interact with magnesium metal to form a barrier on the surface of the Mg metal, inhibiting reversible electrochemical reactions in the cell. An innovative concept to solve this issue is to replace the negative Mg metal electrode with a material compatible with solvents and electrolyte solutions with wider electrochemical stability windows. Mg alloys compounds possess adequate stability in conventional electrolytes and slightly higher potentials than pure Mg metal. Their capacity is smaller than pure Mg, yet still sufficient to provide a substantial increase of the capacity of the battery. The first objective of the thesis is the synthesis of unexplored nanostructured binary or ternary alloys offering higher cycling performance (capacity, coulombic efficiency) than state-of-art materials. The second objective is the strong understanding of the magnesiation/demagnesiation reaction mechanisms and the reactivity towards electrolytes of the unexplored compounds.

Nuclear magnetic resonance and quantum chemistry for the design of innovative biosensors

SL-DRF-17-0337

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM)

Saclay

Contact :

Jean-Pierre DOGNON

Patrick BERTHAULT

Starting date : 01-10-2017

Contact :

Jean-Pierre DOGNON

CEA - DRF/IRAMIS/NIMBE/LSDRM

0169083714

Thesis supervisor :

Patrick BERTHAULT

CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

More : http://iramis.cea.fr/Pisp/patrick.berthault/

More : http://iramis.cea.fr/nimbe/lsdrm/

Nuclear magnetic resonance of hyperpolarized xenon-129 has recently led to high sensitivity molecular imaging and can be used even in non-superficial biological tissues. The laboratory is one of the pioneers in this field that has been able to mark its imprint through twenty publications cited more than 450 times. The approach consists in using molecular systems capable of reversibly encapsulating the noble gas. These host molecules possess a chemical antenna recognizing a biological receptor or an analyte and the large variation of the resonance frequency of the encapsulated xenon gives rise to high sensitivity spectroscopic imaging.

Recently, tools based on ab-initio and DFT calculations allowed us to model the chemical shift of xenon encapsulated in the different reaction intermediates of an H2O2 probe. This work shows that it is possible, with the appropriate theoretical chemistry tools, to access the important parameters of the interaction, even for a heavy atom like xenon. On the one hand, it is important to extend these methods to other xenon-host molecule complexes, and on the other hand to predict the xenon in-out exchange rates, crucial for the sensitivity of the method. This is the subject of this thesis.

Metal Organic frameworks for new generation of Li-air batteries

SL-DRF-17-0375

Research field : Physical chemistry and electrochemistry
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire d'étude des éléments légers (LEEL)

Saclay

Contact :

Suzy SURBLE

Hicham KHODJA

Starting date : 01-10-2017

Contact :

Suzy SURBLE

CEA - DRF/IRAMIS/NIMBE/LEEL

+ 33 1 69 08 81 90

Thesis supervisor :

Hicham KHODJA

CEA - DRF/IRAMIS/NIMBE/LEEL

01 69 08 28 95

More : http://iramis.cea.fr/nimbe/Pisp/suzy.surble/

More : http://iramis.cea.fr/nimbe/leel/

Energy storage will be more essential in the future than it has never been in the past. Therefore, the development of alternative energy is of the utmost importance because our society needs to produce, transport, consume and store energy to keep its high technological level and well-being. Lithium-ion technology holds in this area a prominent place on the market. Nevertheless, its specific capacity and energy density seem to reach their limits and will be insufficient for the long-term needs of our society. It is therefore necessary to develop a new technology of batteries offering new prospects for storage capacity and safety, particularly in the automotive sector. The Li - air batteries are receiving intense interest today due to potentially much higher gravimetric energy storage density compared to others technologies (1700 Wh/kg vs 160 Wh/kg for current Li-ion batteries). However, there are numerous scientific and technical challenges that must be overcome, the most important being the rapid loss of the electrochemical performance after only a few charge cycles. The use of metal-organic framework (MOF) for electrochemical applications is a breakthrough. These compounds have low density, high surface area and high porosity.

The objective of the thesis will be to synthesize new MOF materials, which will present good electrochemical performance. Conventional techniques such as X-ray diffraction, electrochemical and impedance measurements will be used to characterize these materials. For the most promising structures, the electrode formulation will be optimized in order to obtain a complete assembly of Li-air battery.

Characterization of ion pairs by conformation-resolved spectroscopy

SL-DRF-17-0069

Research field : Physical chemistry and electrochemistry
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

(SBM)

Saclay

Contact :

Eric GLOAGUEN

Starting date : 01-09-2017

Contact :

Eric GLOAGUEN

CNRS - DSM/IRAMIS/LIDyL/SBM

01 69 08 35 82

Thesis supervisor :

Eric GLOAGUEN

CNRS - DSM/IRAMIS/LIDyL/SBM

01 69 08 35 82

More : http://iramis.cea.fr/Pisp/70/eric.gloaguen.html

More : http://iramis.cea.fr/LIDYL/SBM/

More : http://iramis.cea.fr/LIDYL/

Ion pairs are ubiquitous in Nature (sea water, aerosols, living organisms). Being the very first step of crystallisation of ionic species and influencing the properties of ion-concentrated solutions or ionic liquids, they also play a key role in countless applications. Although they are met in many areas of Physics, Chemistry and Biology, their characterisation in solution is complicated by the co-existence of several types of pairs and their elusive nature. New techniques can now investigate these objects isolated in the gas phase and address several scientific issues from a new perspective. In this context, the scientific program of this thesis aims at investigating neutral ion pairs by using an approach combining spectroscopy and quantum chemistry calculations. Three directions will be explored:

- Spectroscopic characterization of each type of pairs, and application to the dissociative role of the solvent.

- Description of the first steps of crystallisation of ionic compounds.

- Analysis of the influence of counter-ions on the structure of charged biomolecules.

Plenoptic Ultrafast NanoImaging using a harmonic source

SL-DRF-17-0642

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Hamed MERDJI

Starting date : 01-10-2016

Contact :

Hamed MERDJI

CEA - DRF/IRAMIS/LIDyL/ATTO

0169085163

Thesis supervisor :

Hamed MERDJI

CEA - DRF/IRAMIS/LIDyL/ATTO

0169085163

More : http://iramis.cea.fr/lidyl/Phocea/Membres/Annuaire/index.php?uid=merdji

More : http://iramis.cea.fr/LIDyL/ATTO/

Coherent (or plenoptic) imaging consists in encoding the information about 3D structure of an object (or landscape) by recording the incidence angle of rays arriving on the optical system. TO do that, one commonly uses a lens array placed before the main lens. This technic works very well in the visible range, and is even commercialized by different firms like Lytro in the US (https://www.lytro.com/). CEA, in the framework of the FET H202 European project – VOXEL – proposes to extend this technique to X-rays with nanometer scale spatial and femto/attosecond temporal resolutions. We will use the coherent X-ray high harmonic source developed by the ATTOPHYSIQUE group. This technic will pave the way to the exploration of matter with unprecedented resolutions in time (femto/attosecond) and in space (nanometer). The thesis will consist in developing experimentally and theoretically the plenoptic nano-imaging with ultrafast X-rays.

Photophysics of Hot electrons transfer between plasmonic nanoparticles and molecular adsorbates

SL-DRF-17-0272

Research field : Radiation-matter interactions
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire d'Electronique et nanoPhotonique Organique (LEPO)

Saclay

Contact :

Celine FIORINI

Starting date : 01-10-2017

Contact :

Celine FIORINI

CEA - DRF/IRAMIS/SPEC/LEPO

0169086238

Thesis supervisor :

Celine FIORINI

CEA - DRF/IRAMIS/SPEC/LEPO

0169086238

More : http://iramis.cea.fr/Pisp/celine.fiorini/

More : http://iramis.cea.fr/spec/LEPO/

Beyond the enhancement of photophysical processes (Raman spectroscopy, frequency conversion, fluorescence …) optically excited plasmonic nanoparticles were recently demonstrated to be interestingly used to activate chemical transformations directly and very locally on their surfaces. This opens up many opportunities in the field of selective chemical synthesis, the controlled fabrication of hybrid nanostructures, phototherapy, photocatalysis ... The identification of the parameters enabling to control these chemical reactions induced by plasmons is currently focusing the attention of a large community. The difficulty is to distinguish between various physical phenomena likely to take place, ie (1) the localized heating resulting from the thermalization (electron-phonon interaction) of the hot electrons generated by exciting a NP at its resonance or, (2) direct charge transfer effects between hot electrons and nearby molecules.



The aim of the thesis is to study the mechanisms of hot electron transfer between an excited metal particle with plasmon resonance and a molecular adsorbate placed in proximity, in the absence of solvent (dry way) following a multiphotonic excitation. To this end, we will take advantage of the joint use of complementary characterization means implemented and mastered at CEA / SPEC-LEPO: 2-photon luminescence microscopy (TPL), which has recently been the subject of important developments in the laboratory and photoelectron emission microscopy (PEEM), for which CEA / SPEC-LEPO is a specialist.

Irradiation of isolated collagen by ionizing radiation

SL-DRF-17-0605

Research field : Radiation-matter interactions
Location :

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Saclay

Contact :

Jean-Christophe POULLY

Jean-Yves CHESNEL

Starting date : 01-10-2017

Contact :

Jean-Christophe POULLY

CEA - DRF/IRAMIS/CIMAP/CIMAP

0231454442

Thesis supervisor :

Jean-Yves CHESNEL

Université de Caen - CIMAP/Centre de Recherche sur les Ions, les Matériaux et la Photonique

02.31.45.25.69

More : http://cimap.ensicaen.fr/spip.php?article271

More : http://cimap.ensicaen.fr/spip.php?rubrique15

More : http://cimap.ensicaen.fr

Probing the intrinsic effects of ionizing radiations on biologically-relevant molecular systems is of high fundamental interest, but is also crucial for the understanding of molecular processes underlying radio- and hadrontherapy. Our group has a long standing experience in crossed-beam experiments where photons as well as ions collide with molecular systems in the gas phase. Furthermore, we recently initiated a collaboration with radiobiologists to investigate bystander effects of the irradiation of cartilage, in particular focusing on collagen, the main component of its extracellular matrix. We have already obtained results from beamtimes at the BESSY2 synchrotron (Berlin, Germany), where we irradiated collagen model peptides with VUV and X photons in collaboration with the group of T. Schlathölter (University of Groningen, Netherlands). The selected candidate will thus push further this work by studying collagen triple-helix models in the gas phase and deduce the role of this specific structure in the physics and chemistry induced by irradiation. He/she will have to develop new collaborations in this direction. Furthermore, the main aim of this work will consists of using a new experimental set-up recently validated in our lab in Caen, to irradiate collagen peptides and proteins with heavy ions. For peptides, the results will be compared those obtained with photons, and experimental development will be mandatory to study proteins.

Synthesis and neutron diffraction study of chiral compounds hosting magnetic skyrmions

SL-DRF-17-0635

Research field : Radiation-matter interactions
Location :

Laboratoire Léon Brillouin (LLB)

Groupe Diffraction Poudres (GDP)

Saclay

Contact :

Isabelle MIREBEAU

Starting date : 01-09-2016

Contact :

Isabelle MIREBEAU

CNRS - DRF/IRAMIS/LLB/G3A

01-69-08-60-89

Thesis supervisor :

Isabelle MIREBEAU

CNRS - DRF/IRAMIS/LLB/G3A

01-69-08-60-89

More : http://iramis.cea.fr/llb/Phocea/Membres/Annuaire/index.php?uid=mirebea

More : http://www-llb.cea.fr/

More : https://www.universite-paris-saclay.fr/fr/recherche/laboratoire/institut-de-chimie-moleculaire-et-des-materiaux-dorsay-icmmo

Magnetic skyrmions are spin textures somewhat analogous to vortices, which might become the elementary bricks of future electronics. Although industrial applications mostly deal with thin layers, studying bulk materials yields detailed information about the nature of magnetic interactions, which could be crucial for a fine tuning of the material. Such compounds are often frustrated, resulting in low transitions temperatures TC (a few dozens of Kelvin). Small angle neutron scattering (SANS) allow one to observe such spin textures, and they were historically the first ones to visualize skyrmion lattices. Single crystals neutron studies are crucial to discriminate skyrmion phases from casual helixes.

The thesis at the interface of physics and chemistry consists in the synthesis and neutron study of CoZnMn alloys in poly-crystal and single crystal form, hosting magnetic skyrmions in the neighborhood of TC. Their transition temperatures can go beyond 300K and strongly vary with concentration. The goal is to determine for each compound the magnetic phase diagram, then the spin fluctuations. The thesis will be performed in close collaboration between ICMMO (synthesis, magnetic and X ray study directed by C. Decorse) and LLB (neutron experiments performed at Orphée and ILL-Grenoble, directed by I. Mirebeau and N. Martin)

Photo-ionization spectroscopy resolved on the attosecond timescale

SL-DRF-17-0595

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Pascal SALIERES

Starting date : 01-10-2017

Contact :

Pascal SALIERES

CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Thesis supervisor :

Pascal SALIERES

CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

More : http://iramis.cea.fr/Pisp/pascal.salieres/

More : http://iramis.cea.fr/LIDYL/Phocea/Vie_des_labos/Ast/ast_groupe.php?id_groupe=1149

Recently, the generation of sub-femtosecond pulses, so-called attosecond pulses (1 as=10-18 s), has made impressive progress. These ultrashort pulses open new perspectives for the exploration of matter at unprecedented timescale. Their generation result from the strong nonlinear interaction of short intense infrared (IR) laser pulses (~20 femtoseconds) with atomic or molecular gases. High order harmonics of the fundamental frequency are produced, covering a large spectral bandwidth in the extreme ultraviolet (XUV) range. In the temporal domain, this coherent radiation forms a train of 100 attosecond pulses [1].



With such attosecond pulses, it becomes possible to investigate the fastest dynamics in matter, i.e., electronic dynamics that occur naturally on this timescale. Attosecond spectroscopy thus allows studying fundamental processes such as photo-ionization, in order to answer questions such as: how long does it take to remove one electron from an atom or a molecule? More precisely: how long does it take for an electron wavepacket produced by absorption of an attosecond pulse to exit the atomic/molecular potential? The measurement of such tiny ionization delays is currently a “hot topic” in the scientific community. In particular, the study of the ionization dynamics close to resonances would give access to detailed information on the atomic/molecular structure, such as the electronic rearrangements in the remaining ion upon electron ejection. Recently, we have studied an auto-ionizing resonance, so-called “Fano resonance”. We have shown through 2-photon XUV+IR ionization that it is possible to observe in real time the buildup of the resonance profile [2].



The objective of thesis is to generalize the technique to the study of other types of atomic/molecular resonances, such as shape resonances. Further studies will be devoted to the possibility of controlling resonant ionization by playing on the intensity of the IR laser field superposed on the attosecond pulse. Finally, the measurement of the photoelectron angular distribution, in combination with the temporal information detailed above, will allow the reconstruction of the full 3D movie of the electron ejection.

The experimental work will include the operation of a setup installed in the FAB1 laser of Attolab allowing: i) the generation of attosecond XUV radiation, ii) its characterization using quantum interferometry, iii) its use in photo-ionization spectroscopy (electron detection). The theoretical aspects will also be developed. The student will be trained in ultrafast optics, atomic and molecular physics, quantum chemistry, and will acquire a good mastery of charged particle spectrometry. A background in ultrafast optics, nonlinear optics, atomic and molecular physics is required.

Part of this work will be performed in collaboration with partner French laboratories (ANR CIMBAAD) and members of the MEDEA European Network through joint experiments in the different associated laboratories (Milano, Lund).



References :

[1] Y. Mairesse, et al., Science 302, 1540 (2003)

[2] V. Gruson, et al., Science 354, 734 (2016)

Primary Defects in Halide Perovskites: Effect on Stability and Performance for Photovoltaic Applications

SL-DRF-17-0495

Research field : Radiation-matter interactions
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Bernard GEFFROY

Catherine CORBEL

Starting date : 01-10-2017

Contact :

Bernard GEFFROY

CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 33 43 87

Thesis supervisor :

Catherine CORBEL

CEA - DRF/IRAMIS/LSI/LSI

01 69 33 44 98

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=bgeffroy

More : http://iramis.cea.fr/nimbe/licsen/

A new class of solar cells based on halide perovskite materials (HOIPs) has emerged in 2012 and in only 6 years power conversion efficiencies have rapidly increased from an initial value of around 4% in 2009 to over 22% in early 2016. In perovskite solar cells, the absorber material is made of HOIPs crystals such as CH3NH3PbI3. However, the stability of the materials under operating conditions (light, bias, environment…) is the main challenge to be addressed before commercialization. It has been suggested that ionic migration as well as structural defects in HOIPs could impact optoelectronic performance and affect device operation and long-term stability. In order to provide solutions to such instability, it is essential to understand the role of these defects on HOIPs performance and ageing. For this objective, this project aims to determine the behavior of HOIPs materials where the introduction of primary defects is controlled by using high–energy (0.5-2.5 MeV) electron beams. The sun-light absorption and the carrier collection will be examined as a function of the concentration and nature of the introduced defects. The presence of vacancy-type defects, I.e. defects arising from missing atoms, will be monitored by using positron annihilation spectroscopy.

Temporal measurement of attosecond light pulses generated from plasma mirrors

SL-DRF-17-0399

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Physique à Haute Intensité (PHI)

Saclay

Contact :

Fabien QUÉRÉ

Starting date : 01-10-2017

Contact :

Fabien QUÉRÉ

CEA - DRF/IRAMIS/LIDyL/PHI

01.69.08.10.89

Thesis supervisor :

Fabien QUÉRÉ

CEA - DRF/IRAMIS/LIDyL/PHI

01.69.08.10.89

More : http://iramis.cea.fr/Pisp/fabien.quere/

More : http://iramis.cea.fr/LIDYL/PHI/

When an ultrashort and ultra-intense laser pulse is focused on a solid target, this targets gets strongly ionized, and is thus turned into a dense plasma that specularly reflects the incident laser beam. The target thus behaves as a standard Mirror: this is called a plasma Mirror. For laser intensities higher than 10^16 W/cm^2, due to the highly non-linear response of the plasma, the spectrum of the reflected light contains high-order harmonics of the incident frequency. The broad spectrum formed by the superposition of these harmonics is associated, in the time domain, to a train of attosecond pulses (1 as=10^-18 s). The generation of such pulses, the shortest ones ever obtained, is an extremely active research field, because they are short enough to probe the ultrafast dynamics of electrons in matter. The study of this radiation also provides highly valuable information on the physics of the interaction between plasma mirrors and ultra-intense lasers. The goal of this thesis is to perform the first measurements of the temporal properties of these attosecond pulses, by using and improving some measurement methods that correspond to the present state-of-the-art of ultrafst metrology.

Ultrafast dynamics in materials for solar energy conversion studied by femtosecond optical spectroscopies

SL-DRF-17-0299

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Saclay

Contact :

Elsa CASSETTE

Thomas GUSTAVSSON

Starting date : 01-10-2017

Contact :

Elsa CASSETTE

CNRS - DRF/IRAMIS/LIDYL/DICO

0169081940

Thesis supervisor :

Thomas GUSTAVSSON

CNRS - DRF/IRAMIS/LIDYL/DICO

0169089309

More : http://iramis.cea.fr/LIDYL/Phocea/Membres/Annuaire/index.php?uid=ecassett

More : http://iramis-i.cea.fr/LIDYL/Phocea/Vie_des_labos/Ast/ast_groupe.php?id_groupe=575

This project aims to understand the ultrafast processes of energy conversion and charge transfer in materials for photovoltaic application in order to increase their efficiency and to develop new solar cells. In particular, we will study exciton multiplication through fission in perovskite nanostructures, a mechanism capable of creating several excitons after the absorption of a single high energy photon.

Densification and point defects creation meacanisms in silicate type glasses

SL-DRF-17-0416

Research field : Radiation-matter interactions
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Nadege OLLIER

Starting date : 01-10-2017

Contact :

Nadege OLLIER

CEA - DRF/IRAMIS/LSI

01 69 33 45 18

Thesis supervisor :

Nadege OLLIER

CEA - DRF/IRAMIS/LSI

01 69 33 45 18

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ollier

More : https://portail.polytechnique.edu/lsi/fr/recherche/dielectriques-verres-et-ceramiques-complexes

This subject deals with the understanding of densification effects and point defects creation in silicate type glasses (silica and sodalime glasses) by high pressure application or irradiation and almost combining both effects. Silica glasses is commonly used in optics domain and this work is interesting for radiation hardening of optical fibers of high flux damages of optics for high power laser. We will focus on a better behavior of the structure of densified glasses and on some unclear signature of non-identified point defects. SIRIUS accelerator will be used in order to perform in situ luminescence studies and to study the impact of temperature (20 K) and dose. Complementary techniques will be Raman and IR spectroscopies as well as EPR. This work will be enriched by collaboration with ILM, Lyon(HP) and Linards Skuja (Lativa).

XUV attosecond pulses carrying an angular momentum: synthesis and new spectroscopies

SL-DRF-17-0145

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Thierry RUCHON

Bertrand CARRÉ

Starting date : 01-09-2016

Contact :

Thierry RUCHON

CEA - DRF/IRAMIS/LIDyL/ATTO

0169087010

Thesis supervisor :

Bertrand CARRÉ

CEA - DRF/IRAMIS/LIDyL/ATTO

01 6908 5840

More : http://iramis.cea.fr/Pisp/thierry.ruchon/

More : http://iramis.cea.fr/LIDYL/atto/

More : http://attolab.fr/

Light in the extreme ultraviolet (XUV) is a universal probe of mater, may it be in diluted or condensed phase: photons associated with this spectral range carry energy of 10 to 100 eV, sufficient to directly ionize atoms, molecules or solids. Large scale instruments such as synchrotrons or the lately developed free electron lasers (FEL) work in this spectral range and are used to both study fundamental light matter interaction and develop diagnosis tools. However these instruments do not offer the temporal resolution require to study light matter interactions at their ultimate timescales, which is in the attosecond range (1as = 10-18s). An alternative is offered by the recent development of XUV sources based on high order harmonic generation (HHG). They are based on the extremely nonlinear interaction of a femtosecond intense laser beam with a gas target. Our laboratory has pioneered the development, control and design of these sources providing XUV attosecond pulses.



In this PhD project, we will develop specific setups to allow these attosecond pulse to carry angular momenta, may it be spin or orbital angular momenta. This will open new applications roads through the observations of currently ignored spectroscopic signatures. More precisely, we will focus on the observation of attosecond dynamics, firstly of chiral molecules followed by natural circular dichroism and secondly, on magnetic surfaces dyncamics followed by helical dichroïsms. These two effects are largely unknown to date. While the first application will ask the synthesis of pulses carrying a circular polarization (spin angular momentum), the second request the synthesis of pulses that carry an orbital angular momentum. The PdD will be mainly carried out on the top level Attolab lasers (attolab.fr).



The student will acquire practical knowledge about lasers, in particular femtosecond lasers, and hands on spectrometric techniques of charged particles. He/she will also study strong field physical processes which form the basis for high harmonic generation. He/she will become an expert in attosecond physics. The acquisition of analysis skills, computer controlled experiments skills will be encouraged although not required.

Radiolytic mechanisms of water in cement hydrates and implication for the H2 formation

SL-DRF-17-0167

Research field : Radiation-matter interactions
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Sophie LE CAER

Starting date : 01-09-2017

Contact :

Sophie LE CAER

CNRS - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 58

Thesis supervisor :

Sophie LE CAER

CNRS - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 58

More : http://iramis.cea.fr/Pisp/sophie.le-caer/

More : http://iramis.cea.fr/nimbe/lions/

In the cement matrices used for the packaging of low and medium activity radioactive waste, radiolysis is the origin of H2 production that can lead to a safety risk in the storages. The evaluation of H2 production is currently based on a model considering only the decomposition of free water. This hypothesis neglects all the water molecules present in cement hydrates as constitution (OH-) or crystallization (H2O) water. But the main hydrate, calcium silicate hydrate (C-S-H), is a "gel" with a significant amount of water in all its forms, suggesting a potentially significant H2 release under irradiation. In this context, the radiolytic formation of H2 from C-S-H should be firstly quantified, and, second, the primary reaction mechanisms should be understood in relation to the structure of different C-S-H and, especially, to the different forms of water. The proposed working method is to synthesize several types of C-S-H differing by the respective proportion of the different forms of water, to equilibrate them at a controlled relative humidity and to characterize them in details before and after irradiation. These characterizations will be put in line with the different H2 production yields measured. The chosen materials are crystallized C-S-H models (tobermorite and jennite) or C-S-H more or less amorphous obtained from the hydration of Portland cement and varying by their Ca/Si ratio. Characterization include water vapor sorption-desorption tests, X-ray diffraction, proton and silicon NMR, infrared spectroscopy (from far to mid) at various relative humidity. These results will be put in line with molecular dynamics simulations on these systems.

Radiosensitizers in ion beam therapy: measure of emitted electrons from metallic atoms and nanoparticles upon ion collision

SL-DRF-17-0257

Research field : Radiation-matter interactions
Location :

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP)

Saclay

Contact :

Violaine VIZCAINO

Jean-Yves CHESNEL

Starting date : 01-10-2017

Contact :

Violaine VIZCAINO

CNRS - DRF/IRAMIS/CIMAP/CIMAP

02 31 45 49 91

Thesis supervisor :

Jean-Yves CHESNEL

Université de Caen - CIMAP/Centre de Recherche sur les Ions, les Matériaux et la Photonique

02.31.45.25.69

More : http://cimap.ensicaen.fr/spip.php?article285

More : http://cimap.ensicaen.fr/spip.php?rubrique15

The use of radiosensitizers, including high-Z nanoparticles (Ag, Au, Gd), was proposed to enhance the effects of ionizing radiation in ion beam therapy. The mechanism responsible for such an efficiency enhancement is the important release of electrons from the nanoparticles (NPs) triggered either by the primary ion beam or by secondary charged particles created along the track. We propose to quantify this low energy electron emission by providing absolute doubly differential cross sections (DDCS) in order to better understand the intrinsic properties of NPs under irradiation and the physical processes leading to the efficiency enhancement of radiation damage. To do so, a new crossed beam apparatus is being developed: the target beam (metallic atoms or NPs) crosses orthogonally the projectile ion beam (keV to MeV kinetic energy) produced by the GANIL beamlines. The emitted electrons are extracted orthogonally and analyzed in energy (up to 200eV) and angle by a Velocity Map Imaging spectrometer. The PhD student will be in charge of characterizing this new set-up as well as measuring the first absolute DDCS for metallic atoms and NPs. He (or she) will also participate in the conception of the NPs beam source.

BIOPHYSICAL AND DYNAMICAL STUDY OF CHROMATIN CONFORMATION DURING GENOME REPLICATION

SL-DRF-17-0936

Research field : Soft matter and complex fluids
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Frédéric GOBEAUX

Patrick GUENOUN

Starting date : 01-11-2017

Contact :

Frédéric GOBEAUX

CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 24 74

Thesis supervisor :

Patrick GUENOUN

CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

More : http://iramis.cea.fr/Pisp/frederic.gobeaux/

More : http://iramis.cea.fr/nimbe/lions/

The tridimensional organization of the genome and its dynamics in live cells are decisive to perform its functions. It is crucial to understand them and to identify the parameters controlling them. Current state of the art allows describing the short range (<10 nm) and long range (>250 nm) organization of chromatin conformation in the nucleus. However, there is an intermediate range (10-250 nm) where chromatin organization is difficult to apprehend. This range corresponds to the size of proteic complexes that modify chromatin and harness genome replication.

We propose to monitor cell cultures during genome replication using small angle x-ray scattering. Thanks to a dedicated experimental set-up we will study chromatin conformation dynamics during genome duplication and complement this analysis with numerical simulations (molecular dynamics) so as to correlate chromatin dynamics with that of genome duplication. We will study different cell types to test the generality of our observations.

This project is a collaboration between two teams of physicists and biologists and will consist for the student to reach a dual expertise in both disciplines.

Self-assembled metamaterials made by block copolymers

SL-DRF-17-0814

Research field : Soft matter and complex fluids
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Patrick GUENOUN

Virginie PONSINET

Starting date : 01-11-2017

Contact :

Patrick GUENOUN

CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Thesis supervisor :

Virginie PONSINET

CNRS - Centre de Recherche Paul Pascal (CRPP)

+33(0)5 56 84 56 25

More : http://iramis.cea.fr/Pisp/patrick.guenoun/index.html

More : http://iramis.cea.fr/nimbe/lions/

Metamaterials are "artificial" materials which are created to reach properties inaccessible to natural homogeneous materials. Optical properties like negative refractive indices could be achieved by an adequate structuring of materials at a scale lower than the wavelength of the light. In this PhD work, we shall obtain such a structuration by combining the self-assembly of copolymers on surfaces and the insertion of gold nanoparticles in the copolymer matrix. The copolymer matrix of copolymers provides the nanostructuration and the desired geometry thanks to microphase separation on top of the substrate whereas the gold nanoparticles presence confers the expected optical properties. This PhD thesis project in collaboration between LIONS at CEA Saclay (U. P. Saclay) and the Paul Pascal Research Center (CRPP) in Bordeaux will benefit from both environments to lead an experimental study which will consist in preparing surfaces where cylindrical or bicontinuous phases of copolymers will be directed perpendicularly to the substrate. After synthesis in the laboratory and insertion of gold nanoparticles in the structures, the optical properties of the obtained material will be measured and analyzed for modeling.

Dissipation, cascades and singularities in turbulence

SL-DRF-17-0173

Research field : Soft matter and complex fluids
Location :

Service de Physique de l'Etat Condensé (SPEC)

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX)

Saclay

Contact :

Bérengère DUBRULLE

Starting date : 01-10-2017

Contact :

Bérengère DUBRULLE

CNRS - DRF/IRAMIS/SPEC/SPHYNX

0169087247

Thesis supervisor :

Bérengère DUBRULLE

CNRS - DRF/IRAMIS/SPEC/SPHYNX

0169087247

More : http://iramis.cea.fr/Pisp/berengere.dubrulle/index.html

More : http://iramis.cea.fr/spec/sphynx/

Many phenomena in nature involve motion of viscous flows, which are widely believed to be described by Navier-Stokes equations (NSE). These equations are used for instance in numerical simulations of flows in astrophysics, climate or aeronautics. These equations are the cornerstones of many physical and engineering sciences, and are routinely used in numerical simulations. From a mathematical point of view, however, it is still unclear whether the Navier-Stokes equations are a well-posed problem in three dimensions, i.e. whether their solutions remain regular over sufficient large time or develop singularities.

Historically, the search for singularities in NSE was initiated by Leray who introduced the notion of weak solutions (i.e. in the sense of distribution). This notion was used to prove that the mathematical singular set has a one-dimensional Haussdorff measure equals to zero in space-time. Therefore, if these singularities exist, they must be extremely localized events in space and time. This makes their direct detection an outstanding problem. For some times, the best suggestive evidence of their existence was provided by the observation that the energy dissipation rate in turbulent flows tends to a constant at large Reynolds numbers This observation is at the core of the 1941 Kolmogorov theory of turbulence, and was interpreted by Onsager as the signature of singularities with local scaling exponent $h=1/3$. Later, it was conjectured that the singularities are organized into a multifractal set. Analysis of measurements of 3D numerical or 1D experimental velocity fields showed that the data are compatible with the multifractal picture, with a most probable $h$ close to $1/3$. However, this analysis could not reveal any information on the space-time statistics of (possible) singularities.



A major breakthrough was achieved when Duchon and Robert performed a detailed energy balance for weak solutions of INSE, and compute the contribution stemming from an eventual lack of smoothness. They show that it can be lumped into a single term, that quantifies the "inertial" energy dissipation, i.e. the energy dissipated by non-viscous means.

The purpose of this thesis is to test these mathematical results in a numerical turbulent swirling flow to infer properties of the energy dissipation in a turbulent flow.

3D study of destabilized flows

SL-DRF-17-0528

Research field : Soft matter and complex fluids
Location :

Service de Physique de l'Etat Condensé (SPEC)

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX)

Saclay

Contact :

Gilbert ZALCZER

Romain Monchaux

Starting date :

Contact :

Gilbert ZALCZER

CEA - DRF/IRAMIS/SPEC/SPHYNX

0169083164

Thesis supervisor :

Romain Monchaux

ENSTA Paristech - IMSIA

01.69.31.97.66

More : http://iramis.cea.fr/spec/Phocea/Membres/Annuaire/index.php?uid=zalczer

More : http://iramis.cea.fr/spec/SPHYNX/

Liquid lows under solicitation have always been a subject of fascination, owing to the diversity of the observed effects. A simple flow, at low speed, get more and more complicated when the speed increases, goes through different transitions before becoming turbulent. Owing to newly developed techniques in the domains of fast imaging and fast beam control, it seems possible to get "instantaneous" views of the 3 components of the velocity all over the bulk, even for the supra-laminar domain. We already performed bulk measurements of 2D velocities but have not been able to reconstruct even the laminar flow pattern. Preliminary experiments suggest the possibility of measuring also the third component of the velocity. The experimental work will be first to merge these elements into an operational setup and then study the different flows occurring.

Migration of additives during the formation of polymer membranes - Experimental and numerical analysis of phase separation mechanisms in presence of additives

SL-DRF-17-0837

Research field : Soft matter and complex fluids
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Patrick GUENOUN

Denis BOUYER

Starting date : 01-11-2017

Contact :

Patrick GUENOUN

CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Thesis supervisor :

Denis BOUYER

Université Montpellier 2 - IEM, UMR 5635

04 67 14 91 20

More : http://iramis.cea.fr/Pisp/patrick.guenoun/index.html

More : http://iramis.cea.fr/nimbe/LIONS/

This thesis project aims to acquiring a better understanding of the phenomena of structuration of porous membranes thanks to a coupling between a numerical modeling study and an experimental analysis by optical microscopy. The two main objectives of the project will be (i) to better predict the morphology of the membranes according to the parameters of the process and the formulation, and (ii) to better understand the migration phenomena of the additives used In the development of polymeric membranes.

The simulation of the phase separation will be carried out in several steps using the Cahn and Hilliard model (simplified approach, integration of nonlinear diffusive phenomena, coupling with convective transport). The experimental analysis will be carried out by confocal laser optical microscopy; It will make possible to follow the distribution of an additive in the polymeric structure in formation.

As a predictive tool, the model will make it possible to define a set of suitable operating parameters according to the desired membrane morphology and to help optimize the quantity of additives added. The analysis of the migration phenomena of the additives during the phase separation and within the formed membrane structure will provide a better prediction of the performances of the membranes in the medium and long run.

Optical measurements of dissipation and energy fluxes in turbulent flows

SL-DRF-17-0878

Research field : Soft matter and complex fluids
Location :

Service de Physique de l'Etat Condensé (SPEC)

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX)

Saclay

Contact :

Sébastien AUMAÎTRE

Starting date : 01-10-2017

Contact :

Sébastien AUMAÎTRE

CEA - DRF/IRAMIS/SPEC/SPHYNX

01 69 08 74 37

Thesis supervisor :

Sébastien AUMAÎTRE

CEA - DRF/IRAMIS/SPEC/SPHYNX

01 69 08 74 37

More : http://iramis.cea.fr/Pisp/sebastien.aumaitre/

More : http://iramis.cea.fr/spec/SPHYNX/

The aim of this proposal is the study of power fluctuations in turbulent flow. The usual theoretical approaches have shown that the stationarity of the flow, implying the balance of the power injected large scales with the power dissipated at small scales, constrains the power spectrum of the velocity. However, one needs to go beyond to explain the complexity and the intermittency of turbulent flow. One can consider the statistical properties of the fluctuations of powers involved in turbulent flow. Especially one can explore the correlations implied by the stationarity on the fluctuations of injected and dissipated power and theirs consequences on the structure of the flow. The challenge is to estimate the fluctuations of dissipated power resolved in time. To do so, we would like to develop an innovative optical technics implying diffusive wave spectroscopy and ultra-fast image acquisition. This technics will be complemented by usual measurement technics in order to estimate simultaneously the injected power and to probe the structure of the flow.

Thermoelectric phenomena in ferrofluids

SL-DRF-17-0010

Research field : Soft matter and complex fluids
Location :

Service de Physique de l'Etat Condensé (SPEC)

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX)

Saclay

Contact :

SAWAKO NAKAMAE

Starting date : 01-10-2017

Contact :

SAWAKO NAKAMAE

CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Thesis supervisor :

SAWAKO NAKAMAE

CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

More : http://iramis.cea.fr/Pisp/sawako.nakamae/

More : http://iramis.cea.fr/spec/SPHYNX

Interface Dzyaloshinskii-Moriya interaction physics.

SL-DRF-17-0478

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Mésocopie Modélisation et Thermoélectricité (GMT)

Saclay

Contact :

Cyrille BARRETEAU

Starting date : 01-10-2017

Contact :

Cyrille BARRETEAU

CEA - DRF/IRAMIS/SPEC/GMT

+33(0)1 69 08 38 56

Thesis supervisor :

Cyrille BARRETEAU

CEA - DRF/IRAMIS/SPEC/GMT

+33(0)1 69 08 38 56

More : http://iramis.cea.fr/Pisp/cyrille.barreteau/

More : http://iramis.cea.fr/spec/GMT

The progress of the science and technology of the magnetism of matter is since the 1930’s largely driven by the reduction of dimensions. The physical properties of magnetic material are very dependent on the size and the shape of the sample. The magnetic characteristic of a surface, a thin film, a wire or a nanoparticle are indeed very different and also very far from the one of the bulk. The possibility to grow ultrathin films is at the origin of the discovery of Giant Magnetoresistance which gave rise to the spintronic and its discoverers A. Fert and P. Grunberg were awarded the 2007 Nobel Prize in Physics. Since a few years a magnetic interaction has attracted attention of researchers: The Dzyaloshinskii-Moriya (DMI) interface interaction. This interaction is well known in bulk since many years but its study in magnetic ultrathin films deposited on a nonmagnetic substrate is very recent. It is at the origin of very specific non-collinear magnetic structures such as skyrmions which are fascinating objects that the scientific community hopes to be able to manipulate with a view to create magnetic devices such as memories. However, the fundamental mechanisms at the origin of the interface DMI are still not well understood and the modelling at the atomic scale (electronic structure calculations) is mandatory. In this thesis we propose to use (and develop) electronic structure codes to calculate the interface DMI on systems that will be characterized experimentally. The future PhD student will integrate a theory & modeling team with a long experience in the electronic structure, magnetism and transport properties of nanostructures.

Theoretical study of graphene electrodes for Molecular Electronics

SL-DRF-17-0258

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Mésocopie Modélisation et Thermoélectricité (GMT)

Saclay

Contact :

Yannick DAPPE

Starting date : 01-10-2017

Contact :

Yannick DAPPE

CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Thesis supervisor :

Yannick DAPPE

CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

More : http://iramis.cea.fr/spec/Pisp/yannick.dappe/

More : http://iramis.cea.fr/spec/GMT/

Molecular Electronics constitute nowadays a very active field of research, either for fundamental aspects in these new systems which allow exploring new Physics at the atomic scale, than for the possible applications in terms of innovative electronic devices. Indeed, beyond the ability to reproduce silicon based components (diodes, transistors, …), molecules can also bring new types of electric response due to the great number of quantum degrees of freedom, which are tunable according to the considered molecule. Indeed, the quantum nature of these objects as well as the new associated functionalities open fascinating perspectives to build future electronics. Consequently, those new researches have led to important developments in the field of Molecular Electronics, in particular regarding the control and manipulation of electronic transport through a molecular junction. Most of the molecular junctions are based on molecules connected to metallic electrodes (gold, platinum, silver…). However, it has been demonstrated in several occasions that the connection between molecule and electrode has a non negligible influence on the electric conductance of the system. In that manner, recent developments have proposed to make use of new materials like graphene, which is really well-known for its fantastic electric conduction properties, as electrodes for molecular junctions. Hence, it has been observed that the connection to a graphene electrode allows to significantly increase the junction conductance for long molecular chains, and therefore to reduce the energetic cost of such junction.

The main objective of this PhD lies in this frame by the theoretical study of asymmetric molecular junctions based on graphene or MoS2, as well as the study of molecular wires lifted off a surface using a STM tip. By using Density Functional Theory (DFT), we will determine the equilibrium configuration of the molecular junction and the corresponding electronic properties, before in a second time to calculate the electronic transport from the obtained structures, using a Keldysh-Green formalism. The purpose will be to understand the mechanism of conductance increase with respect to classical junctions, and to compare them to existing experimental results. The different expected behaviorsin those systems allow to study the Physics of electronic transport at the atomic scale, and could be exploited for the conception of new devices at the single molecule scale.

In operando study of ferrite - perovskite multiferroic encapsulated microstructures

SL-DRF-17-0177

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire Nano-Magnétisme et Oxydes (LNO)

Saclay

Contact :

Antoine BARBIER

Starting date : 01-10-2017

Contact :

Antoine BARBIER

CEA - DRF/IRAMIS/SPEC/LNO

01.69.08.39.23

Thesis supervisor :

Antoine BARBIER

CEA - DRF/IRAMIS/SPEC/LNO

01.69.08.39.23

More : http://iramis.cea.fr/Pisp/137/antoine.barbier.html

More : http://iramis.cea.fr/spec/LNO/

More : http://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast_visu.php?id_ast=2545&id_unit=9&id_groupe=179

Perovskite ferroelectric oxides coupled with magnetic ferrites belong to the new class of artificial multiferroic materials. Their high potential for applications in spintronics and energy conversion makes their study a challenging topic. The nature of the coupling, especially during operation under an external field, remains largely unexplored. The proposed thesis work consists of a close collaboration between CEA and SOLEIL synchrotron (HERMES beamline); the student guidance will be equally shared between both institutions. The ferrite inclusions in a single crystalline perovskite film will be realized at CEA by molecular beam epitaxy assisted by an atomic oxygen plasma or thermal treatment. The behaviour of these inclusions under functioning conditions will be examined using the most advanced synchrotron radiations techniques and in particular spectromicroscopy, absorption, X-ray diffraction and magnetic dichroism, respectively on beamlines HERMES, DIFFABS and DEIMOS in a close collaborative approach. The student will acquire skills in ultra-high vacuum techniques, molecular beam epitaxy, magnetometry as well as in the above mentioned state of the art synchrotron radiation techniques.

Local magnetic microscopy by magnetoresistive nanosensor integration

SL-DRF-17-0244

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire Nano-Magnétisme et Oxydes (LNO)

Saclay

Contact :

Aurélie Solignac

Myriam PANNETIER-LECOEUR

Starting date : 01-10-2016

Contact :

Aurélie Solignac

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 95 40

Thesis supervisor :

Myriam PANNETIER-LECOEUR

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 74 10

More : http://iramis.cea.fr/spec/Pisp/aurelie.solignac/

More : http://iramis.cea.fr/spec/LNO/

The use of giant magnetoresistance effect allows developing very sensitive magnetic sensors able to detect magnetic field of the order of nT/vHz. However, to detect magnetic objects with very small dimensions and in a local way, a reduction of the sensor size has to be realized. The use of nanofabrication tools such as electronic lithography allows fabricating active structures down to 50nm sizes. Firstly, the effect of the size reduction on the sensors performances in terms of magnetoresistance and of noise will be studied.

Secondly, the nanometric size sensors developed will be integrated in AFM (Atomic Force Microscope) tip type structures. This integration will allow combining a nanometric magnetic sensors and a scanning probe microscope like AFM, creating an ultra-sensitive and quantitative magnetic microscope.

The PhD aim will be to develop this microscope and to test it, initially, on magnetic structures as domain walls. Then other magnetic objects, for example biologic or steel could be studied by beneficiating from the spatial resolution and the sensitivity at low frequency of the microscope.

Finally, an implementation of the microscope will be the addition of an alternative magnetic field to allow the characterization in an original way of the magnetic surface susceptibility.

Electronic, magnetic and transport properties of two-dimensional organo-metallic molecular networks.

SL-DRF-17-0487

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Groupe Mésocopie Modélisation et Thermoélectricité (GMT)

Saclay

Contact :

Cyrille BARRETEAU

Starting date : 01-10-2017

Contact :

Cyrille BARRETEAU

CEA - DRF/IRAMIS/SPEC/GMT

+33(0)1 69 08 38 56

Thesis supervisor :

Cyrille BARRETEAU

CEA - DRF/IRAMIS/SPEC/GMT

+33(0)1 69 08 38 56

More : http://iramis.cea.fr/Pisp/cyrille.barreteau/

More : http://iramis.cea.fr/spec/GMT

Since the discovery (or rather the exfoliation) of a monolayer of carbon called graphene the number of studies on two-dimensional materials has exploded. It was shown that a large number of materials can exist in monolayers, however, in most cases the synthesis is obtained by deposition on a substrate which generates strain and defects that alter the properties of the intrinsic material. Another alternative recently proposed by chemists consists in growing molecular networks at the liquid/liquid (or liquid/air) interface which allows overcoming the perturbation issues generated by the substrate. The network can be deposited a posteriori on a substrate. The properties of such systems are basically mostly unknown and a modelling work is mandatory to provide guidance to the experimentalists in order to define the most appropriate molecules. Preliminary calculations have shown the extreme versatility of these networks which physical characteristics vary significantly as a function of their structure, chemical composition or electric charge etc. In this thesis we propose to perform a theoretical and modelling effort to elucidate the electronic, magnetic and transport properties of these two-dimensional molecular networks. A strong collaboration with experimental teams will greatly help the definition of the most adequate systems for future applications. The future PhD student will integrate a theory & modeling team with a long experience in the electronic structure, magnetism and transport properties of nanostructures.

Giant tetragonality, local octahedral distortions and chemical switching of the ferroelectric polarization in strained PbTiZrO3 and BiFeO3 thin films studied by X-ray photoelectron diffraction

SL-DRF-17-0336

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS)

Saclay

Contact :

Nicholas BARRETT

Starting date : 01-10-2016

Contact :

Nicholas BARRETT

CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Thesis supervisor :

Nicholas BARRETT

CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

More : http://iramis.cea.fr/Pisp/nick.barrett/

More : http://iramis.cea.fr/spec/lensis/

The fundamental property of ferroelectric (FE) materials is the electrically switchable spontaneous polarization below the Curie temperature. The chemical environment can switch the ferroelectric state, the oxygen partial pressure for example can induce preferential polarization orientation.



X-ray Photoelectron Diffraction combines the chemical sensitivity of core level photoemission with local order sensitivity around the emitting atom and is ideally suited to measure the three dimensional surface distortions in the atomic structure of epitaxial FE films.



The aim is to study and to chemically control the local atomic distortions in the giant pseudo-tetragonal phase of BiFeO3 films grown on substrates with high misfit strain. The huge polarization values, if switchable, would be of great interest in a variety of piezoelectric and ferroelectric applications. However, the very strong pseudo-tetragonality might shift the coercive field beyond breakdown making device manufacture impossible. Chemical switching of the polarization offers an alternative route to reversibly control the FE polarization.



Thin film samples will be grown at the National Institute of Materials Physics (Magurele, Romania) and at the UMPhys CNRS/Thalès. The XPD experimental results will be interpreted thanks to simulations in collaboration with the University of Goias (Brazil).

Magnetic properties of differently-shaped metal nanocrystals

SL-DRF-17-0342

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire d'Electronique et nanoPhotonique Organique (LEPO)

Saclay

Contact :

Fabien SILLY

Starting date :

Contact :

Fabien SILLY

CEA - DRF/IRAMIS/SPEC/LEPO

01 69 08 80 19

Thesis supervisor :

Fabien SILLY

CEA - DRF/IRAMIS/SPEC/LEPO

01 69 08 80 19

More : http://iramis.cea.fr/Pisp/fabien.silly/index.html

More : http://iramis.cea.fr/spec/LEPO/

The structure and shape of metal nanocrystals govern their magnetic properties at the nanometer scale. The objective of this PhD project is to grow differently-shaped metal nanocrystal and investigate their magnetic properties. These structures will be characterized using scanning tunneling microscopy in ultra-high vacuum, spin polarized scanning tunneling spectroscopy and synchrotron spectroscopy. Theses tunable nanostructures are model candidates to study magnetism and observe new magnetic phenomena at the nanometer scale.

Electroluminescence and photoconductivity studies in carbon nanotubes devices

SL-DRF-17-0733

Research field : Solid state physics, surfaces and interfaces
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Arianna FILORAMO

Starting date : 01-09-2017

Contact :

Arianna FILORAMO

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-86-35

Thesis supervisor :

Arianna FILORAMO

CEA - DRF/IRAMIS/NIMBE/LICSEN

01-69-08-86-35

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=filoramo

More : http://iramis.cea.fr/nimbe/LICSEN/

Thanks to their outstanding electrical, mechanical and chemical characteristics, carbon nanotubes have been demonstrated to be very promising building blocks for future nanoelectronic technologies. In addition, recently their optical properties have attracted more attention because of their typical fundamental optical transition in the NIR [1-2] in a frequency range of interest for the telecommunications. The idea is to combine their particular optical features, inferred by their one-dimensional character, with their assessed exceptional transport characteristics for optoelectronics application [3-5]. However, before that this can be realized some fundamental studies are necessary. Here, we will consider the mechanism involved in the electroluminescence and photoconductivity: both the carrier injection and the mechanisms leading to radiative recombination are to be considered. We will perform studies onto semiconducting nanotubes that we will extract from the pristine mixture by a method based on selective polymer wrapping [6-12].



[1] S. M. Bachilo et al. Science 298, 2361 (2002) ;

[2] O’Connell M. J. et al., Science 297, 593 (2002) ;

[3] Freitag et al., NanoLetter 6, 1425 (2006) ;

[4] Mueller et al., NatureNanotech. 5, 27 (2010) ;

[5] S.Wang et al. Nano Letter 11, 23 (2011);

[6] Nish, A. et al. Nat. Nanotechnol. 2, 640 (2007) ;

[7] Chen, F. et al. Nano Lett. 7, 3013 (2007) ;

[8] Nish, A. et al. Nanotechnology 19, 095603 (2008) ;

[9] Hwang, J.-Y. et al., J. Am. Chem. Soc. 130, 3543-3553 (2008) ;

[10] Gaufrès E. et al., Appl. Phys. Lett. 96, 231105 (2010) ;

[11] Gao, J. et al. Carbon 49, 333 (2011);

[12] Tange M. et al. ACS Appl. Mater. Interfaces 4, 6458 (2012)

[13] Sarti F. et al Nano Research 9, 2478 (2016)

Theoretical description of non-linear processes in magnetic materials

SL-DRF-17-0501

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Valérie VENIARD

Starting date : 01-10-2017

Contact :

Valérie VENIARD

CNRS - LSI/Laboratoire des Solides Irradiés

01 69 33 45 52

Thesis supervisor :

Valérie VENIARD

CNRS - LSI/Laboratoire des Solides Irradiés

01 69 33 45 52

More : http://etsf.polytechnique.fr/People/Valerie

More : https://portail.polytechnique.edu/lsi/fr

More : http://etsf.polytechnique.fr/

Second harmonic generation (SHG) is a process where two photons are absorbed by a material and a photon of twice the energy of the incoming photons is emitted. This spectroscopy is used to study the optical properties of materials because it reveals additional information, compared with linear optical spectroscopies. Due to dipole selection rules, SHG is forbidden in centro-symmetric materials and it is possible to obtain a structural and electronic characterization for these systems. However the absence of time-inversion symmetry in antiferromagnetic materials leads to new contributions in second harmonic generation, thus revealing the arrangement of spins in the solid. SHG becomes a powerful tool to study of ultra-fast demagnetization processes.



There are few satisfactory theoretical descriptions for SHG in magnetic materials, since spin-orbit coupling, electron-electron interactions and local field effect must be treated on the same footing. To study this process, we have developed a formalism within the framework of Density Functional Theory. In this thesis, we will focus on the electron-electron interaction, described by an exchange-correlation kernel fxc which must be approximated. We will explicitly deal with spin-orbit coupling, describing electronic orbitals by a 2D spinor. We will study these effects for a typical antiferromagnetic material, namely Cr2O3.

Characterization and control of charged ferroelectric domain walls

SL-DRF-17-0220

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS)

Saclay

Contact :

Nicholas BARRETT

Starting date : 01-10-2017

Contact :

Nicholas BARRETT

CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Thesis supervisor :

Nicholas BARRETT

CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

More : http://iramis.cea.fr/Pisp/nick.barrett/

More : http://iramis.cea.fr/spec/lensis/

Ferroic oxides are materials displaying one or more order parameters: ferroelectric, ferroelastic and/or magnetic. They possess intrinsic domains separated by domain walls which can have completely different physical properties compared to those of the bulk material. Exploring these properties might allow envisaging domain walls as the active element of the materials properties.

In a ferroelectric, charged domain walls could be a new paradigm for post-CMOS electronics since they can be considered as nanometric metallic conductors in a highly insulating dielectric medium. The thesis work will focus on how these walls respond to external electric or mechanical stress.

The student will use photoelectron and low energy electron spectromicroscopy to study the chemical and electronic surface structure of domain walls with nanometric spatial resolution. Dedicated sample-holders will allow the operando analysis under electric or mechanical stress. The samples will be provided by the Institut de Chimie Moléculaire et Matériaux d'Orsay. The experiments will be done in collaboration with the UMPhys CNRS/Thalès and the Institute of Nanotechnologies of Lyon.

Tunable multicomponent supramolecular magnetic self-assembly for spintronics

SL-DRF-17-0350

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire d'Electronique et nanoPhotonique Organique (LEPO)

Saclay

Contact :

Fabien SILLY

Starting date : 01-10-2015

Contact :

Fabien SILLY

CEA - DRF/IRAMIS/SPEC/LEPO

01 69 08 80 19

Thesis supervisor :

Fabien SILLY

CEA - DRF/IRAMIS/SPEC/LEPO

01 69 08 80 19

More : http://iramis.cea.fr/Pisp/fabien.silly/index.html

More : http://iramis.cea.fr/spec/LEPO/

The autonomous ordering and assembly of molecules on atomically well-defined surfaces is an important technique for evolving applications in nanotechnology. The objective of this PhD project is to create tunable open molecular architectures to control the ordering of magnetic nano-objects on metal surfaces. The idea is to use experimental parameters to switch to one magnetic structure to another. These structures will be characterized using scanning tunneling microscopy in ultra-high vacuum and spin polarized scanning tunneling spectroscopy. Theses tunable nanostructures are model candidates to study magnetism at the nanometer scale.

Oxide nanoparticles: advanced modeling and simulation of optical or ferroelectric properties

SL-DRF-17-0175

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Marc HAYOUN

Starting date : 01-10-2017

Contact :

Marc HAYOUN

CEA - DRF/IRAMIS/LSI

0169334533

Thesis supervisor :

Marc HAYOUN

CEA - DRF/IRAMIS/LSI

0169334533

More : http://www.lsi.polytechnique.fr/accueil/laboratoire/trombinoscope/

More : http://www.lsi.polytechnique.fr/accueil/recherche/physique-et-chimie-des-nano-objets/

More : http://www.lsi.polytechnique.fr/

Nanoparticles (NP) can be characterized as collections of a few hundred to a few thousand atoms, intermediate between atomic and macroscopic scales. Their properties are different from those of the bulk material and evolve according to their size. We have shown in the case of oxide (MgO) NPs that the macroscopic approach is inadequate and must be supplemented by modeling at the atomic scale.

The aim of the proposed study is to explore the effect of particle size on the dielectric, optical and ferroelectric properties of oxide NPs at different temperatures and frequencies. The results will contribute to applications in the fields of energy, memory FeRAM (Ferroelectric Random Access Memory) and medicine.

The subject will be attacked by first considering the intrinsic properties of individual NPs and to evidence behaviors and generic effects that may evolve with symmetry and shape. We shall then study the properties of NPs located near a surface, in proximity to another NP or inserted into a host matrix. The aim is to highlight attenuation or enhancement effect of dielectric, IR absorption or ferroelectric properties.

The computation of NP properties will be performed by the technique of molecular dynamics (MD) simulation, using phenomenological potentials or ab initio description of the interaction forces between atoms. Quantum effects appearing at temperatures lower than Debye temperature will be included using specifically developed MD techniques based on a quantum thermostat.

New electronic states in single crystals and thin films of iridates

SL-DRF-17-0120

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire Nano-Magnétisme et Oxydes (LNO)

Saclay

Contact :

Jean-Baptiste MOUSSY

Dorothée COLSON

Starting date : 01-10-2017

Contact :

Jean-Baptiste MOUSSY

CEA - DRF/IRAMIS/SPEC/LNO

01-69-08-92-00

Thesis supervisor :

Dorothée COLSON

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 73 14

More : http://iramis.cea.fr/spec/Pisp/jean-baptiste.moussy/

More : http://iramis.cea.fr/spec/LNO/

More : http://iramis.cea.fr/spec/Pisp/dorothee.colson/

Iridates (e.g. Sr2IrO4, Sr3Ir2O7 ...) have recently attracted attention due to the presence of a strong spin-orbit coupling and strong electronic interactions that give rise to original physical properties such as, the high critical temperature superconductivity or the state of topological insulator. Especially, the identification of a topological phase in these oxides should allow exploring new ways to manipulate the spin of electrons, a key point for applications in spintronics.

The aim of this thesis project is to study the emergence of Mott insulators, magnetic and topological properties in single crystals, single layers and heterostructures of iridates. More precisely, the objectives of the thesis will be to synthesize new compounds of the iridates family (e.g.Sr3Ir2O7) in the form of single crystals and thin films to explore their electronic properties (new topological phases, new Mott insulators, etc).For the development of single crystals, the self-flux method will be chosen. Sr3Ir2O7 crystals of pure compound will be synthesized and electron doping will be achieved through cationic substitutions (for example: Sr/La). Then, the crystals will be characterized by different techniques: X-ray diffraction, electron microprobe and magnetic measurements (SQUID, VSM magnetometry). For thin films, we will use a new ultrahigh vacuum growth technique developed in the laboratory: the pulsed laser deposition (PLD) method with a laser beamworking in the nanosecond or femtosecond regime. PLD is a well-known technique for the epitaxial growth of oxide thin films (cuprates, manganites, ferrites ...), which is based on the ablation by a laser beam of the target of the material to be deposited on a monocrystalline substrate. A peculiar attention will be given to the structural and physical properties of oxide thin films by using in situ electron diffraction (RHEED), photoemission spectroscopy (XPS/UPS), or ex situ techniques such as near-field microscopy (AFM), magnetism (SQUID,VSM). The electronic properties of samples (crystals and films) will then be studied in collaboration with the LPS-Orsay, including electrical measurements and the quantum spin Hall effect, which is the signature of a topological state.

Ab initio description of resonant inelastic X-ray scattering

SL-DRF-17-0520

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Francesco Sottile

Starting date : 01-10-2017

Contact :

Francesco Sottile

Ecole Polytechnique - UMR 7642

0169334549

Thesis supervisor :

Francesco Sottile

Ecole Polytechnique - UMR 7642

0169334549

More : http://etsf.polytechnique.fr/people/francesco

More : http://etsf.polytechnique.fr/

The aim of this thesis project is to develop the theory and software that allow for a predictive description of Resonant Inelastic X-ray Scattering (RIXS) experiments.



To achieve this we will combine a strong expertise in advanced theoretical approaches to electronic excitations, computational developments, and knowledge on different classes of materials. Most of RIXS data are today obtained at transition metal and Oxygen edges. The reason is an outstanding interest in so-called strongly correlated transition-metal oxides, both for their intrinsic complexity that makes their study intellectually challenging and for the prospect of novel applications (high-Tc superconductors, colossal magneto-resistance, transparent conducting oxides, etc). If, on one side, this historical attention has been very beneficial for the transition metal oxides and related fields, on the other side, it's worth underlining the huge potential for application of RIXS (both experimentally and theoretically) on other materials and fields.



The PhD student will develop an ab initio method to tackle this kind of spectroscopy and a particular emphasis will be dedicated to the analysis and data interpretation.

Ground state properties of correlated materials : a new approach

SL-DRF-17-0522

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Lucia REINING

Starting date : 01-10-2017

Contact :

Lucia REINING

CNRS - LSI/Laboratoire des Solides Irradiés

0169334553

Thesis supervisor :

Lucia REINING

CNRS - LSI/Laboratoire des Solides Irradiés

0169334553

More : http://etsf.polytechnique.fr/people/lucia

More : http://etsf.polytechnique.fr

This thesis is part of a research line which has the scope to build a new theoretical approach that will allow us to describe efficiently and precisely a wide range of properties of so-called "strongly correlated" materials: these are materials for which the effects of the Coulomb interaction between electrons are particularly important. Static mean field theories such as Density Functional Theory (DFT) fail to describe excitations in these materials qualitatively and quantitatively. Moreover, even ground state properties, such as the equilibrium volume, are very difficult to predict with standard functionals. Recently, we have proposed a non-perturbative approach for the calculation of many-body Green's functions to predict electronic excitations. The PhD student will explore this idea in order to access also ground state properties, as an alternative to both DFT and standard approximations to many-body perturbation theory, such as the widely used GW approximation.



As a first ambitious application of the new approach, we envisage to study transitions to symmetry breaking ground states, in particular charge density waves.

Antiferromagnet spintronics: towards an active control of the magnetic anisotropy

SL-DRF-17-0020

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire Léon Brillouin (LLB)

Groupe Diffraction Monocristaux (GDM)

Saclay

Contact :

Alexandre Bataille

Stéphane Andrieu

Starting date : 01-10-2016

Contact :

Alexandre Bataille

CEA - DRF/IRAMIS/LLB/GDM

01 69 08 58 98

Thesis supervisor :

Stéphane Andrieu

Université de Lorraine - Institut Jean Lamour, département P2M, équipe Nanomagnétisme et Electronique de spin

03 83 68 48 24

More : http://iramis.cea.fr/llb/Pisp/alexandre.bataille/

More : http://www-llb.cea.fr/index.php

More : http://ijl.univ-lorraine.fr/recherche/departement-physique-de-la-matiere-et-des-materiaux-p2m/nanomagnetisme-et-electronique-de-spin/

Reducing the electrical consumption of everyday electronic devices is a major societal issue, which can only be performed through a technological breakthrough. Developing spintronics devices where antiferromagnetic layers (materials exhibiting a magnetic ordering but no net magnetization) would play an active role is one of the directions recently pursued notably through the use, and eventually control, of their magnetic anisotropy. The main obstacle on this road is that measuring the magnetic ordering of an antiferromagnet is quite difficult. The most direct technique to do so is to use neutron diffraction, which can be used on epitaxial thin films thanks to recent experimental developments. The present PhD thesis will benefit from the access to a unique vector magnet which will allow the simultaneous study of magnetic anisotropy by neutron diffraction and of magneto-transport properties. This will lead to detailed knowledge of the key physical phenomena and should eventually allow an active control of the anisotropy which could be used in devices.

Electron-phonon coupling in low dimensional graphene-based systems: theory and numerical simulation

SL-DRF-17-0499

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Christine GIORGETTI

Valérie VENIARD

Starting date : 01-10-2017

Contact :

Christine GIORGETTI

CNRS - Laboratoire des Solides irradiés UMR 7642

01 69 33 45 01

Thesis supervisor :

Valérie VENIARD

CNRS - LSI/Laboratoire des Solides Irradiés

01 69 33 45 52

More : http://etsf.polytechnique.fr/People/Christine

More : http://etsf.polytechnique.fr/

The design of new opto-electronic devices requires understanding of the properties of valence electrons. In nano-objects, these properties are unique due to the electronic confinement in low dimensional systems. They can be studied by the simulation of electronic excitations via the dielectric function. The approaches we develop and use are ab-initio theories and calculations, which means without adjustable parameter, making them extremely reliable and flexible. They are based on the use of the Bethe-Salpeter equation, which takes into account the electron-hole interaction.



Graphene and carbon nanotubes exhibit exceptional electronic properties, due to the linearly dispersing bands at the Fermi level (Dirac electrons). For this reason, such materials exhibit very low energy excitations, for which the question of the influence of phonons arises.



The formalism used and developed in our ab initio calculations is based on the electron-boson coupling, where the boson is the electron-hole pair. In this thesis, we propose to generalize the formalism to electron-phonon coupling, where the boson describes the phonon.

NB : the candidate must contact the lab before 15th of march.



Contacts :

christine.giorgetti@polytechnique.edu,

valerie.veniard@polytechnique.edu

SL-DRF-17-0489

Research field : Solid state physics, surfaces and interfaces
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Nathalie VAST

Starting date : 01-10-2017

Contact :

Nathalie VAST

CEA - DRF/IRAMIS/LSI/LSI

01 69 33 45 51

Thesis supervisor :

Nathalie VAST

CEA - DRF/IRAMIS/LSI/LSI

01 69 33 45 51

More : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=nvast

More : http://www.lsi.polytechnique.fr/accueil/recherche/theorie-de-la-science-des-materiaux/

More : http://www.researchgate.net/publication/30516420_Proprits_vibrationelles_du_bore_alpha_et_du_carbure_de_bore

B4C Boron carbide is a high-valued ceramics used for mechanical shielding used e.g. for the protection of aircrafts. The material looses its mechanical strength when impacted beyond the Hugoniot Elastic Limit [1] and this limits its use. An explanation of the loss of mechanical strength of B4c has been given by quantum chemistry calculations [2-4]. The knowledge gained by these theoretical investigations has enable the team to design a new material with enhanced mechanical properties [5,6]. The objective of this PhD work is to achieve an experimental proof of the existence of the ne material, and to characterize its mechanical properties.





Bibliography :

[1] Dynamic behavior of boron carbide, T. Vogler, W. Reinhart and L. Chhabildas, J. Appl. Phys. 95, 4173 (2004).

[2] Boron carbides from first-principles, N. Vast, J. Sjakste, E. Betranhandy, J. Phys.: Conf. Ser. 176, 012002 (2009).

[3] Mechanical properties of icosahedral boron carbide explained from first principles,

R. Raucoules, N. Vast, E. Betranhandy, and J. Sjakste, Phys. Rev. B 84, 014112 (2011).

[4] Ab initio study of defective chains in icosahedral boron carbide B4C

E. Betranhandy, N. Vast, et J. Sjakste, Solid State Sciences 14, 1683 (2012).

[5] Antoine Jay, Nathalie Vast, Jelena Sjakste, and Olivier Hardouin Duparc, Carbon-rich icosahedral boron carbide designed from first principles, Applied Physics Letters 105, 031914 (2014).

[6] Carbure de bore à stabilité mécanique accrue et procédé de fabrication,

A. Jay, N. Vast, O. Hardouin Duparc and J. Sjakste,

WO Patent App. PCT/EP2014/066,570, (2015).

https://www.google.fr/patents/WO2015022202A1?cl=fr&dq=nathalie+vast+synthèse&hl=fr&sa=X&ved=0CDsQ6AEwA2oVChMIgqiKl_ujxwIViucaCh1LdwBW

Water photo-electrolysis assisted by an internal potential

SL-DRF-17-0046

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire Nano-Magnétisme et Oxydes (LNO)

Saclay

Contact :

Hélène MAGNAN

Antoine BARBIER

Starting date : 01-10-2017

Contact :

Hélène MAGNAN

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 94 04

Thesis supervisor :

Antoine BARBIER

CEA - DRF/IRAMIS/SPEC/LNO

01.69.08.39.23

More : http://iramis.cea.fr/Pisp/helene.magnan/

More : http://iramis.cea.fr/spec/LNO/

More : http://iramis.cea.fr/Phocea/Vie_des_labos/Ast/ast_visu.php?id_ast=1996&id_unit=0&id_groupe=196

Photo-electrolysis is a very seductive solution to produce hydrogen using solar energy. Metal oxides are promising candidates for photoanode, but simple oxides present some limiting factors which can explain their relatively low efficiency for hydrogen production.



In this experimental thesis, we propose to use the spontaneous electric field of a ferroelectric compound to better separate photogenerated charges within the photoanode. In this study, we will investigate model samples (epitaxial thin films prepared by molecular beam epitaxy) and will study the influence of the electric polarization orientation with respect to the surface of the electrode (upward, downward, unpolarized, multi domains) on the photo-electrochemical efficiency. Moreover in order to understand the exact role of electrical polarization, we will measure the lifetime of the photogenerated charges and the electronic structure for the different state of polarization using synchrotron radiation. This thesis work is in the framework of long term research project where the CEA is associated with synchrotron SOLEIL, and University of Bourgogne for a modelisation of the systems.

Biomagnetic signal recordings with spin electronics sensors

SL-DRF-17-0262

Research field : Solid state physics, surfaces and interfaces
Location :

Service de Physique de l'Etat Condensé (SPEC)

Laboratoire Nano-Magnétisme et Oxydes (LNO)

Saclay

Contact :

Myriam PANNETIER-LECOEUR

Starting date : 01-10-2017

Contact :

Myriam PANNETIER-LECOEUR

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 74 10

Thesis supervisor :

Myriam PANNETIER-LECOEUR

CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 74 10

More : http://iramis.cea.fr/Pisp/myriam.pannetier-lecoeur/

More : http://iramis.cea.fr/spec/LEPO/

More : http://www.magnetrodes.com

Spin electronics, which exhibits transport properties depending on the magnetic field, has been used at SPEC to build sensors dedicated to the detection of magnetic signature of the information transmission in excitable cells (cardiac cells and neurons). We have though detected the cardiac magnetic signal thanks to Giant Magneto Resistance (GMR)-based sensors [Appl. Phys. Lett. 2011].



To increase the signal acquisition speed, it will be necessary to enhance the sensors sensitivity by the use of Magnetic Tunnel Junctions (MTJs), which can exhibit magnetoresistance ratio up to 250% at room temperature (vs 10% for GMR).



The PhD will develop devices based on MTJs for the detection of neuronal activity at various scales (from few neurons up to tens of thousands of neurons at the scalp surface). The MTJs stack will be realized on our new thin film deposition system. The probes, fabricated in the laboratory, will be tested in the SPEC magnetically shielded room, to evaluate their intrinsic performances, and then applied to in vivo neuronal recordings and whole brain measurements on Magneto-Encephalography (MEG, passive magnetic recordings at the surface of the scalp) in collaboration with Neurospin laboratory.



These magnetic recordings will allow a multi-scale imaging of neuronal currents, in particular to investigate from the cell level to the brain scale low frequency components of the neuronal signal (1/f noise), already observed in electro-encephalography and MEG recordings but not yet fully understood.

Understanding of long term corrosion for the storage of radioactive waste: study of the mechanisms by multi-scale analysis of archaeological objects

SL-DRF-17-0300

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire archéomatériaux et prévision de l'altération (LAPA)

Saclay

Contact :

Florence Mercier

Delphine Neff

Starting date : 01-10-2016

Contact :

Florence Mercier

CNRS - DRF/IRAMIS/NIMBE/LAPA

01.69.08.47.01

Thesis supervisor :

Delphine Neff

CEA - DRF/IRAMIS/NIMBE/LAPA

01.69.08.33.40

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=fmercier

More : http://iramis.cea.fr/nimbe/lapa/

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=dneff

Within the framework of the storage of the radioactive waste, steel overpacks would be corroded in an anoxic environment. To size them on several thousand years, it is necessary to establish predictive models of corrosion. However to be validated, these models have to take into account the studied mechanisms of corrosion either on simulations in laboratory, or on systems corroded in real conditions. In this last case, archaeological analogues stemming from sites of excavation in which the geochemical conditions are close to those of the storage are studied. They will constitute the set of samples of this thesis in addition with laboratory experiment ones. The physical and chemical properties of corrosion layers, heterogeneous at the micrometer scale, will be studied at the corresponding scale of interest regards the phenomena studied. The crystal structure will be determined by coupling of techniques at microscale in hyperspectral imaging mode (SEM-EDS, µSRaman) and nanoscale (TEM STXM under synchrotron radiation) and their local and global conductive and electrochemical properties through the C-AFM (nano), the SECM (micro) and chrono-amperometry (object scale) in particular. Finally, the transport properties of the oxidizing species in the corrosion layers will be examined through the X-ray tomography (micro), the FIB-tomo (nano) and during re-corrosion experiments with tracers of these systems. The obtained data will be used to refine the predictive modelling of these systems.

Multifonctionnal protein/nanoparticle assemblies

SL-DRF-17-0842

Research field : Ultra-divided matter, Physical sciences for materials
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l'Energie (NIMBE)

Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS)

Saclay

Contact :

Jean-Philippe RENAULT

Starting date : 01-09-2017

Contact :

Jean-Philippe RENAULT

CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

Thesis supervisor :

Jean-Philippe RENAULT

CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

More : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=jrenault

More : http://iramis.cea.fr/nimbe/lions/

Protein nanoparticle interactions have been extensively studied these recent years. It is now conceivable to design NP protein assemblies in order to exploit their respective properties. Such assemblies may give access to completely new materials, combining biological functions and optical or magnetic properties. The objective of this thesis will be to develop such assemblies, to characterize them and to use them as bricks in 3D manufacturing processes.

 

Retour en haut