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PhD subjects

53 sujets IRAMIS

Dernière mise à jour :


• Analytic chemistry

• Atomic and molecular physics

• Chemistry

• Green and decarbonated energy incl. bioprocesses and waste valorization

• Health and environment technologies, medical devices

• Instrumentation

• 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

• Theoretical Physics

• Ultra-divided matter, Physical sciences for materials

 

Novel concepts for inelastic neutron scattering experiments on a compact source

SL-DRF-23-0435

Location :

Laboratoire Léon Brillouin (LLB)

Groupe 3 Axes (G3A)

Saclay

Contact :

Alain MENELLE

SYLVAIN PETIT

Starting date : 01-10-2023

Contact :

Alain MENELLE
CEA - DSM/IRAMIS/LLB

0169089699

Thesis supervisor :

SYLVAIN PETIT
CEA - DRF/IRAMIS/LLB

01 69 08 60 39

Personal web page : https://www-llb.cea.fr/Pisp/sylvain.petit/

Laboratory link : https://iramis.cea.fr/llb/NFMQ/

More : https://iramis.cea.fr/llb/Phocea/Vie_des_labos/Ast/ast_sstechnique.php?id_ast=2755

Compact neutron sources have been proposed as facilities able to provide neutron beams having sufficient flux to study condensed matter. If the mean intensity in the beams will be lower to the one currently available on medium power reactors, the use of pulsed beams will enable a much more efficient use of the neutrons produced. Inelastic neutron scattering is a unique probe of the dynamics of the materials. During this project, we will investigate the performances of the various known geometries of inelastic neutron scattering instruments. We will define and propose the best-adapted instrument for the study of a particular scientific problem. Simulations using the MacStass or Vitess software will be undertaken and demonstration experiment of the efficiency of the concept will be proposed.
Hemoglobin polymerization and diffusion in different hemoglobin mixtures HbYxHbS(1-x) with Y=At, A0, F…

SL-DRF-23-0418

Location :

Laboratoire Léon Brillouin (LLB)

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Stéphane Longeville

Starting date : 01-10-2023

Contact :

Stéphane Longeville
CEA - DRF

01 69 08 75 30

Thesis supervisor :

Stéphane Longeville
CEA - DRF

01 69 08 75 30

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=longevil

Laboratory link : https://iramis.cea.fr/llb/MMB/

Sickle cell disease (SCD) is a genetic disorder of the blood, causing anemia. It results from the polymerization of a mutated hemoglobin, the oxygen-carrying protein found in red blood cells (RBCs), which causes the soft cells to deform into a rigid sickle shape under certain circumstances. Because the deformed cells induced by the polymerization will clog the blood capillaries, it induces an increase in blood pressure and ultimately degeneration of the various organs.



Pharmacological treatments for sickle cell anemia include hydroxyurea, a molecule that promotes the synthesis of fetal hemoglobin (HbF) which leads to a mixture of hemoglobin HbFxHbS(1-x) in the blood, with HbF partially inhibiting polymerization of HbS. Gene therapy is also used for the treatment of this disease by stimulating the production of therapeutic hemoglobin (HbAt), or normal hemoglobin (HbA0). In collaboration with the Department of Genetic Diseases of the Red Blood Cell at Henri-Mondor hospital, we propose to study the effect of the addition of different types of hemoglobin on the polymerization process as well as the kinetics of oxygen capture at RBC level. This model study is directly linked to the treatments developed to cure this disease and aim to try to better understand them from a molecular point of view.This topic is developed in cooperation with Technical University of Munich.
Parahydrogen hyperpolarization and liquid-liquid extraction for more sensitive and resolved NMR

SL-DRF-23-0732

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)

Saclay

Contact :

Gaspard HUBER

Starting date : 01-09-2023

Contact :

Gaspard HUBER
CEA - DRF/IRAMIS/NIMBE/LSDRM

01 69 08 64 82

Thesis supervisor :

Gaspard HUBER
CEA - DRF/IRAMIS/NIMBE/LSDRM

01 69 08 64 82

Personal web page : https://iramis.cea.fr/Pisp/gaspard.huber/

Laboratory link : https://iramis.cea.fr/nimbe/lsdrm/

For the analysis of a mixture of organic molecules in solution, Nuclear Magnetic Resonance (NMR) is, with mass spectrometry, one of the two most used analytical techniques. NMR is often considered to be more quantitative, more reproducible, and more able to identify a solute. However, it lacks sensitivity and resolution. The sensitivity can be increased by employing the particular properties of parahydrogen to create a so-called hyperpolarized state, which transiently but considerably increases the NMR signal. Regarding resolution, it can be notably improved by the use of multidimensional NMR spectroscopy, which should be fast in the case of the analysis of hyperpolarized species. Liquid-liquid extraction, a very frequently used separation process, involves two immiscible phases in which the solutes are distributed according to their affinity. Provided it is fast enough, it allows specific observation of hyperpolarized solutes in each phase, as shown in a preliminary study for a chloroform/water system. The aim of this thesis project is to develop this approach combining hyperpolarization by parahydrogen and extraction, to extend it to new biphasic systems and to apply it to the detection, identification and quantification of very dilute solutes. The ultimate goal is to apply this methodology to samples that contain in essence many solutes, such as those from synthetic chemistry or metabolomics.
Generalized Angular Momentum in Attosecond physics: theoretical and experimental studies

SL-DRF-23-0393

Research field : Atomic and molecular physics
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Thierry Ruchon

Starting date : 01-09-2023

Contact :

Thierry Ruchon
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087010

Thesis supervisor :

Thierry Ruchon
CEA - DRF/IRAMIS/LIDyL/ATTO

0169087010

Personal web page : https://iramis.cea.fr/LIDYL/Pisp/thierry.ruchon/

Laboratory link : https://iramis.cea.fr/LIDYL/ATTO/

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

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.



During this PhD project, we will develop specific setups to allow these attosecond pulse to carry angular momenta, may it be spin, orbital or generalized angular momenta. This will open new applications roads through the observations of currently ignored spectroscopic signatures. However, we will set the focus on the fundamental aspects of light-matter interaction in the highly nonlinear regime with angular momenta involved, in particular on beams with unusual topologies such as Möbius strips.

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.



Detailed subject at the web page: http://iramis.cea.fr/LIDYL/Pisp/thierry.ruchon/
In situ and real time characterization of nanomaterials by plasma spectroscopy

SL-DRF-23-0402

Research field : Atomic and molecular physics
Location :

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

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Marc BRIANT

Starting date : 01-10-2023

Contact :

Marc BRIANT
CEA - DRF/IRAMIS/NIMBE

01 69 08 53 05

Thesis supervisor :

Marc BRIANT
CEA - DRF/IRAMIS/NIMBE

01 69 08 53 05

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=mbriant

Laboratory link : https://iramis.cea.fr/nimbe/ledna/

The objective of this Phd is to develop an experimental device to perform in situ and real time elemental analysis of nanoparticles during their synthesis (by laser pyrolysis or flame spray pyrolysis). Laser-Induced Breakdown Spectroscopy (LIBS) will be used to identify the different elements present and their stoichiometry.



Preliminary experiments conducted at LEDNA have shown the feasibility of such a project and in particular the acquisition of a LIBS spectrum of a single nanoparticle. Nevertheless, the experimental device must be developed and improved in order to obtain a better signal to noise ratio, to increase the detection limit, to take into account the different effects on the spectrum (effect of nanoparticle size, complex composition or structure), to automatically identify and quantify the elements present.



In parallel, other information can be sought (via other optical techniques) such as the density of nanoparticles, the size or shape distribution.
Structure-property relationship in graphene nanoparticles

SL-DRF-23-0002

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 : 01-10-2023

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

Personal web page : http://iramis.cea.fr/Pisp/stephane.campidelli/

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

Graphene as a constituent of graphite was close to us for almost 500 years. However, it is only in 2005 that A. Geim and K. Novoselov (Nobel Prize in 2010) reported for the first time the obtaining of a nanostructure composed by a single layer of carbon atom. The exceptional electronic properties of graphene make it a very promising material for applications in electronic and renewable energies.



For many applications, one should be able to modify and control precisely the electronic properties of graphene. In this context, we propose to synthesize chemically graphene nanoparticles and study their absorption and photoluminescence properties. This project will be developed in collaboration with Physicists so the candidate will work in a multidisciplinary environment.
Porphyrin-based nanostructures

SL-DRF-23-0001

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 : 01-10-2023

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

Personal web page : http://iramis.cea.fr/Pisp/stephane.campidelli/

Laboratory link : http://iramis.cea.fr/nimbe/licsen/

The aim of this project is the synthesis of new molecular structures based on porphyrins for the formation of 0D, 1D and 2D nanostructures. Porphyrins are an important class of molecules that are essential to life through oxygen transport or photosynthesis. Beyond, their importance in Nature, porphyrin derivatives exhibit outstanding optical, electronic, chemical and electrochemical properties that make them promising candidates for applications in catalysis, electrocatalysis, optoelectronics and medicine.



In this project, the porphyrins will be studied in collaboration with several groups of Physicists in order to fabricate 1D or 2D covalent networks on surface via the "bottom-up" approach and to study their electronic and optical properties.
Utilization of gases from CO2 for the synthesis of high added value products

SL-DRF-23-0324

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

Saclay

Contact :

Emmanuel NICOLAS

Thibault CANTAT

Starting date : 01-10-2023

Contact :

Emmanuel NICOLAS
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 26 38

Thesis supervisor :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Personal web page : http://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=enicolas

Laboratory link : http://iramis.cea.fr/nimbe/lcmce/

More : https://iramis.cea.fr/Pisp/thibault.cantat/

The industrial synthesis of chemical products is currently based on the oxidation of fossil compounds. In the current context of energy transition and reduction of the dependence on petroleum products, new ways of carbon sources must be used to maintain the production of these compounds essential to our societies. CO2 is a good candidate, but is not very reactive. Its conversion into CO, coupled with the production of H2 by electrolysis, allows the formation of syngas (CO:H2 mixture) which is a reactive gas allowing the synthesis of numerous chemical products, among others thanks to the Fisher-Tropsch process.



We propose in this thesis project to design new catalysts for the synthesis of alkylamines by Fisher-Tropsch reaction on amines, using syngas from renewable sources. The PhD student will search for new catalysts, optimize them, testing them in the Fisher-Tropsch reaction on amines. The objective will be to have a catalyst that is efficient, selective, and not very sensitive to contaminants such as O2 or H2O. Once this system is optimized, the catalyst will be tested in devices to be designed and built, allowing the use of real syngas supplied by other groups at CEA, formed by gasification of biomass for example.
Search for hidden magnetic textures in high-Tc superconducting cuprates

SL-DRF-23-0111

Research field : Chemistry
Location :

Laboratoire Léon Brillouin (LLB)

Groupe 3 Axes (G3A)

Saclay

Contact :

Dalila Bounoua

Philippe Bourges

Starting date : 01-10-2023

Contact :

Dalila Bounoua
CEA - DRF/IRAMIS/LLB/G3A

0169085181

Thesis supervisor :

Philippe Bourges
CEA - DRF/IRAMIS/LLB/G3A

0169086831

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=dbounoua

Laboratory link : https://www-llb.cea.fr/NFMQ/

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

The highest superconducting temperatures achieved so far at ambient pressure are found in a class of unconventional superconductors, namely, copper oxides. These materials exhibit a very complex electronic phase diagram dominated by the so-called “pseudo-gap” (PG) phase, a mysterious state of matter thought to play a key role in the emergence of superconductivity. Despite decades of intense investigations, the origin of this PG phase remains an unsolved mystery. It hosts electronic instabilities such as an intra-unit cell magnetism interpreted as the hallmark of a quantum magneto-electric state of matter that takes the form of “loop currents”.



Recently, we discovered that such a state could also lead to the formation of a new type of magnetic correlations within the CuO2 planes. The combination of both kinds of magnetism yields a magnetic texture that may play a crucial role in the PG physics and that has remained hidden to experimental probes up to now. These new magnetic correlations highlight another piece of the high-Tc superconductivity puzzle paving the way towards new investigations.



We propose a PhD project at Laboratoire Léon Brillouin in collaboration with Service de Physique de l’Etat Condensé (Saclay), divided into two experimental parts aiming at a systematic study of these novel magnetic correlations. The first part of the work will be devoted to the crystal growth of several cuprates compounds by means of the travelling solvent floating zone technique. The second part will concern the systematic study of the exotic loop current quantum magnetism in the grown single crystals using polarized neutron scattering.
Hydroborane and borohydride synthesis by hydrogenolysis for hydrogen storage

SL-DRF-23-0365

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

Saclay

Contact :

Alexis MIFLEUR

Thibault CANTAT

Starting date : 01-10-2023

Contact :

Alexis MIFLEUR
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 57 43

Thesis supervisor :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Personal web page : https://iramis.cea.fr/Pisp/thibault.cantat/Alexis_Mifleur.php

Laboratory link : https://iramis.cea.fr/nimbe/

More : https://iramis.cea.fr/Pisp/thibault.cantat/index.php

Hydrogen is an excellent energy storage medium, especially in the context of an energy transition based on intermittent renewable energies. However, the problem of its storage and transport arises. Several technologies are currently being explored and the storage of hydrogen in solid materials is an option that has several advantages. Borohydrides, in particular those of alkaline metals, are stable solid materials allowing to store a significant quantity of hydrogen in mass proportion (19 wtH2% for LiBH4, 10 wtH2% for NaBH4). However, their use is still limited because of the very energy consuming synthesis and recycling.



We propose in this project to develop new methodologies to generate boron hydrides from hydrogen in order to immobilize the latter in solid materials for energy storage purposes. The transformation of B-X (X:O,Cl) bonds to their B-H equivalents is a real challenge due to the high affinity of boron with oxygen and the high hydricity of the target compounds which make them reactive hydride donors. Similar work has been described at the LCMCE and by other groups for the synthesis of hydrosilanes and relies on transition metal catalysts or boron-based organocatalysts.



This project will allow the PhD student to develop advanced skills in homogeneous catalysis, characterization of molecular complexes, and gas manipulation.



Translated with www.DeepL.com/Translator (free version)
Innovative signle-atom catalysts for hydrogenation and dehydrogenation of CO2 and LOHCs.

SL-DRF-23-0385

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

Saclay

Contact :

Caroline GENRE

Thibault CANTAT

Starting date : 01-10-2023

Contact :

Caroline GENRE
CEA - DRF/IRAMIS/NIMBE/LCMCE


Thesis supervisor :

Thibault CANTAT
CEA - DRF/IRAMIS/NIMBE/LCMCE

01 69 08 43 38

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=cgenre

Laboratory link : https://iramis.cea.fr/Pisp/thibault.cantat/index.php

More : https://iramis.cea.fr/nimbe/LCMCE/

Single-atom catalysts (SAC) are solid catalysts in which all the active metal atoms are isolated and stabilized on a support, or by an alloy with another metal. The activity is carried by isolated metal atoms, their selectivity is therefore excellent, and the qualities of SACs approach those of homogeneous catalysts while offering the advantages of robustness and ease of handling of solid catalysts. SACs, which allow a high economy of catalytic metals, are good candidates for the implementation of transformations promoting the circular carbon economy and the storage of energy by the hydrogen vector. In particular, they can play an important role for CO2 hydrogenation as well as for hydrogenation and dehydrogenation reactions of liquid organic hydrogen carriers (LOHC), which are an essential element for the transport and storage of energy by the hydrogen vector. However, they remain rather poorly described for these transformations, and the existing examples mostly involve noble metals (Pd, Pt, Au).

The objective of this thesis is twofold. On one hand, it aims at synthesizing and characterizing innovative isolated atom catalysts based on non-noble metals (Ru, Fe, Mn, Co, Cu) capable of catalyzing the reversible hydrogenation of C=O bonds in CO2 and the dehydrogenative coupling of alcohols with water and of alcohols between them. On the other hand, it aims at exploring the possibilities of systems based on alcohol + water/carboxylic acids as LOHC.

The work will consist in synthesizing, characterizing and testing the catalytic activity of different single atom catalysts. The student will be trained in the techniques of synthesis under inert atmosphere, catalysis in pressurized reactors, as well as in the use of various analytical techniques: SEM, HR-TEM, HAADF-TEM, EDX, XPS, XRD

Stability of efficient triple-mesoscopic perovskite solar cells and modules under real outdoor working conditions

SL-DRF-23-0165

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 :

Frédéric Oswald

Starting date : 01-10-2023

Contact :

Frédéric Oswald
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 21 49

Thesis supervisor :

Frédéric Oswald
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 21 49

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=foswald

Laboratory link : https://iramis.cea.fr/nimbe/licsen/

To successfully enter the photovoltaic market, perovskite solar cells are still facing several tough challenges. Scalability of the processes and stability of the devices need to be ensured. The latter especially has been one of the main causes of skepticism for a long time and is still underestimated in most studies.



Outdoor operational conditions are rarely considered and only few reports can be found. All reports show that, as testing time increase, devices suffer both reversible and more importantly irreversible degradations, which potentially are not detected in a constant temperature, constant one-sun irradiance Maximum Power Point (MPP) tracking procedure, confirming the necessity for outdoor testing under real operational conditions.



This thesis relies on : design, fabrication and characterization of devices to be placed on outdoor test bench for testing under operational conditions.

Chemical reactivity of polymer matrices during aging: formation of unintended compounds and implications for plastics recycling

SL-DRF-23-0044

Research field : Chemistry
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 :

Stephanie Devineau

Jean-Philippe RENAULT

Starting date : 01-09-2023

Contact :

Stephanie Devineau
CEA - LIONS


Thesis supervisor :

Jean-Philippe RENAULT
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=sdevineau

Laboratory link : https://iramis.cea.fr/nimbe/lions/

Recycling the 460 million tons of plastics produced each year is a major environmental and energy challenge of the 21st century. The use of recycled plastics is an important lever for reducing the overall CO2 emissions associated with the production and processing of new plastics. However, our ability to recycle plastics remains severely limited by the appearance of new chemical compounds during the aging of the materials to be recycled. In this thesis, we propose to study the aging of plastic additives by combining a historical study and an experimental approach. In a first approach, we will document the compositions and transformation processes of plastics from 1950 onwards, and, from dated samples, the new compounds formed during aging. In a second approach, we will simulate the aging processes by controlled irradiation, in order to reconstitute the reaction chains. The products of natural and artificial aging will be studied in terms of toxicity.
Biogaz irradiation system

SL-DRF-23-0585

Research field : Green and decarbonated energy incl. bioprocesses and waste valorization
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 :

Marie GELEOC

Jean-Philippe RENAULT

Starting date :

Contact :

Marie GELEOC
CEA - DRF/IRAMIS/NIMBE/LIONS


Thesis supervisor :

Jean-Philippe RENAULT
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 15 50

Personal web page : https://iramis.cea.fr/Pisp/marie.geleoc/

Laboratory link : https://iramis.cea.fr/nimbe/lions/

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

In today's energy mix, gas is an immediately available, storable energy that is supported by a very large distribution network. It is possible to completely replace fossil gas with 100% renewable gas by 2050. However, the quality of biogas is much more fluctuating than that of fossil gases and "power to gas". Radiolysis (degradation by ionising radiation) of impurities could be a method of choice to carry out this purification in a simple way, or even to propose alternative storage methods by functionalising the biomethane.
Cellular level characterization of a vector-based anticancer therapy by exploiting 3H-14C dual labeling, single cell capture in microfluidic chips and beta detection

SL-DRF-23-0244

Research field : Health and environment technologies, medical devices
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 :

Florent Malloggi

laurent Devel

Starting date : 01-09-2023

Contact :

Florent Malloggi
CEA - DSM/IRAMIS/NIMBE/LIONS

+3316908 6328

Thesis supervisor :

laurent Devel
CEA - DRF/JOLIOT/DMTS/SIMOS/LBC

+33169089565

Personal web page : https://iramis.cea.fr/nimbe/Pisp/florent.malloggi/

Laboratory link : https://iramis.cea.fr/nimbe/index.php

More : https://joliot.cea.fr/drf/joliot/recherche/DMTS/SIMOS

Using a mixture of cells isolated from an animal tumor that has been injected with a radiolabelled anti-cancer drug, we propose to quantify the exact dose of the drug accumulated in each cell of the tumor. Such an approach will make it possible to answer an essential question in pharmacology: to relate the observed effects (therapeutic and undesirable) to the dose of the drug delivered, in this case at the level of the single cell (cancer cells), but also all the other cell types present in the tumor tissue. We will build on our recent developments in antibody and molecular radiolabelling, cells capture on microfluidic devices and beta-imaging.
Stream processing for data reduction

SL-DRF-23-0351

Research field : Instrumentation
Location :

Service de Physique de l’Etat Condensé (SPEC)

Plateforme de Support à la Recherche

Saclay

Contact :

Mathieu THEVENIN

Starting date :

Contact :

Mathieu THEVENIN
CEA - DRF/IRAMIS/SPEC/PSR

+33 (0) 1 69 08 5887

Thesis supervisor :

Mathieu THEVENIN
CEA - DRF/IRAMIS/SPEC/PSR

+33 (0) 1 69 08 5887

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=mthevenin

Laboratory link : https://iramis.cea.fr/

More : https://www.linkedin.com/in/mathieu-thevenin-2275b03/

The power consumption of computing devices is due to 1) the computational parts 2) the memory accesses and 3) the control logic. The computing part is increasing due to the increase of the volume of data and algorithmic complexity, which also affects the control logic and memory accesses. Some computing paradigms allow a slight reduction of memory access: in-memory computing and stream processing. The first integrates computing elements directly into memory, thus saving read-write accesses before and after the computation since it can be done on-the-fly. The second processes the data directly in the datapath or in a bus, in a dataflow mode, without requiring access to any external memory. Both approaches may be combined. Stream computing also enables near-sensor compressed-sensing allowing realtime processing of huge amount of data without requiring storing and postprocessing. This way, it forms a key element for energy saving. We propose to study coconception of code associated to computer architectures to obtain a slight reduction of memory accesses by combining stream processing and in-memory computing. The use-case we propose is based on the design a of programmable digital signal processor used in next generation instrumentation (quantum physics, nuclear and particle physics, radar) or convolutional IA computing to detect events or features that requires extremely high data bandwidth on several channels, typically >16 > 4GSPs; extremely low latency. Both hardware architecture and software programming paradigm and impact on compilation will be studied. The objective is to develop new computing software/hardware paradigm that combines in-memory computation and stream processing, the programming model and the implementation of demonstration tools. A Proof-of-Concept based on modern FPGA (Zynq Ultrascale) and ASIC (partnership with CentraleSupelec) is expected at the end of the Ph.D. This PoC would allow to study the of different type of hardwares (as well already implemented into the FPGA as customly designed during the Ph.D.) to obtain power consumption figures.
Development of bioactive intracranial implants: from laboratory to industry

SL-DRF-23-0315

Research field : Materials and applications
Location :

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

Laboratoire Innovation, Chimie des Surfaces Et Nanosciences (LICSEN)

Saclay

Contact :

Guy DENIAU

Starting date : 01-02-2023

Contact :

Guy DENIAU
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 21 11

Thesis supervisor :

Guy DENIAU
CEA - DRF/IRAMIS/NIMBE/LICSEN

01 69 08 21 11

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=deniau

Laboratory link : https://iramis.cea.fr/nimbe/licsen/

More : https://lvts.fr/

Background: This project follows a work supported by the Foundation for Medical Research (2018-2022) where we showed the relevance

of modifying the surface of platinum coils (intracranial implants used to treat aneurysms) in order to accelerate aneurysmal healing. This

was demonstrated in vivo by covalent grafting of a polysaccharide, fucoidane, on the surface of the coils.



Objectives of the thesis

The objectives of the thesis project are the following:

1- Optimize the coating of coils allowing a development under GMP (Good Manufacturing Practices) conditions and adapt the method to

an industrial process.

2- To fully characterize the coating in terms of density, thickness and regularity using physicochemical techniques (ATG, DSC, contact

angle, elemental analysis) and optical imaging (biphotonic imaging, scanning electron microscopy, AFM) and spectroscopic techniques

(EDS, XPS).

3- To validate the conditions retained by implantation of the modified coils in a rabbit aneurysmal model.

Partners: UMR NIMBE LICSEN, BALT Company, LVTS Inserm U1148 and XLIM UMR CNRS 7252, CHU Limoges.
Electroactive carbon support for the fabrication of low platinum loading catalysts

SL-DRF-23-0318

Research field : Materials and applications
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 : 01-10-2022

Contact :

Bruno JOUSSELME
CEA - DRF/IRAMIS/NIMBE/LICSEN

0169 08 91 91

Thesis supervisor :

Bruno JOUSSELME
CEA - DRF/IRAMIS/NIMBE/LICSEN

0169 08 91 91

Personal web page : https://iramis.cea.fr/Pisp/bruno.jousselme/

Laboratory link : https://iramis.cea.fr/nimbe/licsen/

The large-scale use of proton exchange membrane fuel cells (PEMFCs) for vehicle engines requires the development of new catalysts. Indeed, the high costs of PEMFCs are mainly linked to the use of a large amount of a noble metal, the platinum, as a catalyst for electrochemical reactions in order to obtain sufficient performance. This Ph.D work deals with the synthesis and the optimization of new catalysts having only a small amount of Pt supported on a carbonaceous material also exhibiting catalytic activity toward the reduction of oxygen. These nitrogen-enriched support carbons comprising a non-noble metal associated with a tiny amount of Platinum should ultimately lead to inexpensive materials. The objective of the Ph.D work is therefore to synthesize and optimize on a large scale carbonaceous catalytic supports and to quantify the number of active sites for the manufacture of catalysts with low platinum loading.
Detection of a single Rare-Earth-Ion Spin by a Superconducting-Qubit-based Single

SL-DRF-23-0422

Research field : Mesoscopic physics
Location :

Service de Physique de l’Etat Condensé (SPEC)

Groupe Quantronique (GQ)

Saclay

Contact :

Emmanuel FLURIN

Starting date : 01-09-2023

Contact :

Emmanuel FLURIN
CEA - DRF/IRAMIS/SPEC/GQ

0622623862

Thesis supervisor :

Emmanuel FLURIN
CEA - DRF/IRAMIS/SPEC/GQ

0622623862

Personal web page : https://iramis.cea.fr/Pisp/emmanuel.flurin/

Laboratory link : https://iramis.cea.fr/spec/GQ/

More : https://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast.php?t=fait_marquant&id_ast=3409

The Phd subject is part of a quantum computing research project aiming at proposing new robust quantum bits that can be interfaced with the superconducting quantum technologies. We explore impurities trapped in solids as extremely long-lived quantum bits.



The crystalline defects of materials can be apprehended as naturally trapped ions in an inert crystalline environment. Due to their immobility and their isolation in the crystal lattice, the electronic and nuclear spins of these ions exhibit excellent coherence times, ranging from a few seconds for electrons to a few hours for nuclei. These systems are thus excellent candidates for encoding quantum information. Superconducting circuits constitute one of the most successful technological platforms for quantum computation. Quantum bits are encoded in artificial electromagnetic oscillators, they are easily controllable and integrable. However, their coherence time does not exceed a few hundreds of microseconds and their manufacture lack of reproducibility, this is one of the main barriers toward the development of processors of more than 100 qubits.



The quantronics group, a pioneer of superconducting circuits, is engaged in a long-term research project which aims at interfacing circuits with the electronic and nuclear spin of a unique crystal defect and thus combine the robustness of natural elements with the integrability of artificial circuits. We recently demonstrated for the first time the detection and manipulation of a single electron spin using a transmon superconducting qubit as a single microwave photon detector [1,2,3]. In this experiment, the single spin is carried by an erbium ion in a scheelite crystal exhibiting a record coherence time of three milliseconds. To extend the spin coherence time to the second timescale, its full natural extent, we propose here to develop a superconducting tunable coupler that can couple and decouple the detector from the spin in a few tens of nanoseconds. Based on the new coupler, we propose to detect and manipulate single nuclear spins in the vicinity of the ion for which coherence could reach hours.
Quantum magnetotransport in shaped topological insulator nanowires

SL-DRF-23-0364

Research field : Mesoscopic physics
Location :

Service de Physique de l’Etat Condensé (SPEC)

Groupe Mésocopie Modélisation et Thermoélectricité (GMT)

Saclay

Contact :

Cosimo Gorini

Starting date : 01-10-2023

Contact :

Cosimo Gorini
CEA - DRF/IRAMIS/SPEC/GMT

+33 1 69 08 73 46

Thesis supervisor :

Cosimo Gorini
CEA - DRF/IRAMIS/SPEC/GMT

+33 1 69 08 73 46

Personal web page : https://iramis.cea.fr/spec/Pisp/cosimo.gorini/

Laboratory link : https://iramis.cea.fr/spec/GMT/

Mesoscopic physics is the realm of micron-size objects composed of trillions of constituents, yet behaving as single quantum entities. An example thereof are 3D topological insulator nanowires, whose insulating bulk is enclosed by highly conducting Dirac-like surface states. Electrons can cross the wires only propagating on their surfaces, and at low temperatures they do so as quantum waves of (pseudo)relativistic nature. The magnetotransport properties of the wires are thus ruled by intereference. The latter is determined/modulated by external magnetic fields and by the Berry curvature of the system, as demonstrated in a recent collaboration with experimentalists from the Universitaet Regensburg (Germany).



Soon afterwards we also showed that the geometrical shape of a nanowire can have dramatic consequences on its magnetotransport properties. Crucially, in shaped topological insulator nanowires electrons propagate on a curved surface, and may thus feel effective gravitational effects. Such emerging gravity takes place on scales which are comparable to the characteristic quantum scales of the system, much as in black holes – nanowires can however be built in labs with current technology, black holes not quite.



Among the numerous open questions in this rapidly growing field, two are most relevant for this project: (i) How are Dirac surface states modified in curved space? (ii) Can a quantum transport signature of effective gravitational nature be singled out in a realistic setup? To answer these both analytical and numerical methods (tight-binding simulations) will be employed.

SL-DRF-23-0740

Research field : Molecular biophysics
Location :

Laboratoire Léon Brillouin (LLB)

Groupe Biologie et Systèmes Désordonnés

Saclay

Contact :

Véronique ARLUISON

Starting date : 01-04-2023

Contact :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Thesis supervisor :

Véronique ARLUISON
Université de Paris - DRF/IRAMIS/LLB/GBSD

01 69 08 32 82

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=varluiso

Laboratory link : http://iramis.cea.fr/LLB/MMB/

Ab initio simulation of catalysts for green chemistry

SL-DRF-23-0719

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)

Saclay

Contact :

Rodolphe POLLET

Patrick BERTHAULT

Starting date : 01-10-2023

Contact :

Rodolphe POLLET
CEA - DRF/IRAMIS/NIMBE/LSDRM

01 69 08 37 13

Thesis supervisor :

Patrick BERTHAULT
CEA - DRF/IRAMIS/NIMBE/LSDRM

+33 1 69 08 42 45

Personal web page : https://iramis.cea.fr/Pisp/rodolphe.pollet/

Laboratory link : https://iramis.cea.fr/nimbe/lsdrm/

Catalysis is today at the core of chemical industrial applications. For example, the conversion of nitrile to amide, which is relevant in pharmaceuticals, agrochemicals, synthetic chemistry and polymer chemistry, by hydration requires an efficient catalyst due to its slow kinetics. For environmental reasons, it is crucial to discover catalysts without transition metals, neither toxic nor corrosive, and cheap. One example of such catalyst is hydroxide choline.



During this thesis, the student will learn how to perform ab initio molecular dynamics simulations coupled with a method which can reconstruct the free-energy landscape of the hydration reaction for different aromatic nitriles in different in silico experimental conditions. He or she will also have to perform quantum chemistry calculations at a level that can describe all the required intra and intermolecular interactions. This theoretical approach has already been successfully used within our team to describe other chemical reactions in aqueous solution and will be applied to the innovative field of green chemistry.
Thermoelectric energy conversion control via coordination chemistry of transition metal redox ions in ionic liquids

SL-DRF-23-0400

Research field : Physical chemistry and electrochemistry
Location :

Service de Physique de l’Etat Condensé (SPEC)

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

Saclay

Contact :

Sawako NAKAMAE

Veronika Zinovyeva

Starting date : 01-10-2022

Contact :

Sawako NAKAMAE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Thesis supervisor :

Veronika Zinovyeva
Université Paris Saclay - Laboratoire de Physique des 2 infinis Irène Joliot-Curie, CNRS-UMR 9012


Personal web page : https://iramis.cea.fr/Pisp/sawako.nakamae/

Laboratory link : https://iramis.cea.fr/spec/sphynx/

Thermoelectricity, a materials’ capability to convert heat in to electric energy has been known to exist in liquids for many decades. Unlike in solids, this conversion process liquids take several forms including the thermogalvanic reactions between the redox ions and the electrodes, the thermodiffusion of charged species and the temperature dependent formation of electrical double layer at the electrodes. The observed values of Seebeck coefficient (Se = - DV/DT, the ratio between the induced voltage (DV) and the applied temperature difference (DT)) are generally above 1 mV/K, an order of magnitude higher than those found in the solid (semiconductor) counterpart. The first working example of a liquid-based thermoelectric (TE) generator was reported in 1986 using Ferro/ferricyanide redox salts in water.



However, due to the low electrical conductivity of liquids, its conversion efficiency was very low, preventing their use in low-temperature waste-heat recovery applications. The outlook of liquid TE generators brightened in the last decade with the development of ionic liquids (ILs). ILs are molten salts that are liquid below 100 °C. Compared to classical liquids, they exhibit many favorable features such as high boiling points, low vapour pressure, high ionic conductivity and low thermal conductivity accompanied by higher Se values. More recently, an experimental study by IJCLab and SPEC revealed that the complexation of transition metal redox couples in ionic liquids can lead to enhancing their Se coefficient by more than a three-fold from -1.6 to -5.7 mV/K, one of the highest values reported in IL-based thermoelectric cells. A clear understanding and the precise control of the speciation of metal ions therefore is a gateway to the rational design of future thermoelectrochemical technology.



Based on these recent findings, we proposes to further study the coordination chemistry of transition metal redox ions in ILs and mixtures. A long-term goal associated to the present project is to demonstrate the application potential of liquid thermoelectrochemical cells based on affordable, abundant and environmentally safe materials for thermal energy harvesting as an energy efficiency tool.
Solid-state batteries based on composite polymer-ceramic electrolytes : multi-scale characterization and understanding of phenomena at interfaces

SL-DRF-23-0607

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 :

Saïd Yagoubi

Thibault CHARPENTIER

Starting date : 01-10-2023

Contact :

Saïd Yagoubi
CEA - DRF/IRAMIS/NIMBE/LEEL

+ 33 1 69 08 42 24

Thesis supervisor :

Thibault CHARPENTIER
CEA - DRF/IRAMIS/NIMBE/LSDRM

33 1 69 08 23 56

Personal web page : http://iramis.cea.fr/Pisp/said.yagoubi/

Laboratory link : http://iramis.cea.fr/nimbe/leel/

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

Lithium-ion batteries, widely present in our daily lives, have revolutionized portable applications and are now used in electric vehicles. However, the development of new generations of batteries for future applications in transport and storing electricity from renewable sources is vital to mitigating climate change.



Sodium is more abundant on earth than lithium and therefore attractive in particular for large-scale stationary storage applications. Lithium-ion technology is generally considered as the preferred solution for applications requiring high energy density, while sodium-ion technology is particularly attractive for applications requiring power.

However, liquid electrolyte batteries present environmental risks such as leaks and can occasionally experience safety problems. Faced with the requirements concerning the environment and safety, solid-state batteries based on solid electrolytes can provide an effective solution while meeting battery energy storage needs. The barriers to overcome allowing the development of all-solid-state battery technology consist mainly in the research of new chemically stable solid electrolytes with good electrical, electrochemical and mechanical performance. For this goal, this thesis project aims to develop “ceramic / polymer” composite solid electrolytes with high performance and enhanced safety. Characterizations by electrochemical impedance spectroscopy (EIS) will be carried out in order to understand the cation dynamics (by Li+ or Na+) at the macroscopic scale in composite electrolytes, while the local dynamics will be probed using advanced techniques of Solid state NMR (23Na / 7Li relaxation, 2D NMR, in-situ NMR & operando). Other characterization techniques such as X-ray and neutron diffraction, XPS, chronoamperometry, GITT ... will be implemented for a perfect understanding of the structure of electrolytes as well as aging mechanisms at the electrolyte / electrolyte and electrolyte/electrode interfaces of the all-solid battery.



Key words: composite solid electrolyte, all-solid-state battery, interfaces, multiscale characterization, dynamics of Li + and Na + ions, electrochemical performance, solid-state NMR, X-ray / neutron diffraction.

Optimization of an extreme light source to study QED dominated plasma states and to pursue technological applications

SL-DRF-23-0387

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Physique à Haute Intensité (PHI)

Saclay

Contact :

Henri VINCENTI

Starting date : 01-10-2023

Contact :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Thesis supervisor :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Personal web page : https://iramis.cea.fr/Pisp/henri.vincenti/

Laboratory link : https://iramis.cea.fr/LIDYL/PHI/

More : https://ecp-warpx.github.io/

Nowadays, femtosecond lasers are the most intense light sources available on Earth, with a power that can reach that of the solar radiation over an area as large as Australia and that can be focused down to focal spots having the diameter of a human hair. These extreme radiation sources are a valuable tool for the study exotic states of matter, but also as a "driver" of secondary sources of compact and ultra-short particles or light.



Despite these remarkable properties, femtosecond lasers still lack the intensity required to explore new fundamental regimes where the laser-matter or laser-quantum vacuum interaction becomes dominated by strong-field Quantum ElectroDynamic (QED) effects. These QED regimes are found for example around some astrophysical objects such as black holes and neutron stars. Moreover, femtosecond lasers typically have a wavelength of ~ 1 micrometer, but some potential technological applications (e.g., photolithography) require much smaller wavelengths, of the order of ten nanometers.



In order to manipulate the properties of femtosecond lasers and overcome these barriers, we are studying optical devices called "relativistic plasma mirrors", which can convert a laser pulse into X-UV radiation, while considerably boosting its intensity by Doppler effect.



This multi-disciplinary thesis project concerns the optimization of the “plasma mirror” physical system in order to improve the properties of the boosted laser beams and to enable the use of these boosted lasers for the above mentioned applications.



The activity will rely on Particle-In-Cell numerical simulations with the open-source code “WarpX“ on the latest exascale class supercomputers to determine the optimal parameters for the generation of boosted beams. An auxiliary code development activity is foreseen to support the simulation campaigns. The simulations will be essential to guide experiments that will be performed on our 100 TW laser facility, UHI100, with controlled temporal contrast, which is essential for the realization of this type of experiments, and then on PW-class lasers (e.g. Apollon at École Polytechnique or other international facilities).



The PhD student will have the opportunity to be part of a dynamic team with strong national and international collaborations. He/she will also acquire the necessary skills to participate in laser-plasma interaction experiments in international facilities. Finally, he/she will acquire the required skills to contribute to the development of a complex software written in modern C++ and designed to run efficiently on the most powerful supercomputers in the world. The development activity will be carried out in collaboration with the team led by Dr. J.-L. Vay at LBNL (US).



Bibliography:

> A.Myers et al. “Porting WarpX to GPU-accelerated platforms” Parallel Computing, 108, 102833, 2021

> L.Fedeli et al. “Probing Strong-Field QED with Doppler-Boosted Petawatt-Class Lasers” Phys. Rev. Lett. 127, 114801, 2020

> H.Vincenti “Achieving Extreme Light Intensities using Optically Curved Relativistic Plasma Mirrors” Phys. Rev. Lett. 123, 105001, 2019

> H Vincenti et a. “Optical properties of relativistic plasma mirrors” Nat. Comm. 5 : 3403, 2014
Spatio-temporal control of the high order harmonic emission from crystals

SL-DRF-23-0319

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Dynamique et Interactions en phase COndensée (DICO)

Saclay

Contact :

David Gauthier

Willem Boutu

Starting date : 01-10-2023

Contact :

David Gauthier
CEA - DRF/IRAMIS/LIDyL/BME


Thesis supervisor :

Willem Boutu
CEA - DRF/IRAMIS/LIDYL/DICO

0169085163

Personal web page : https://iramis.cea.fr/Pisp/willem.boutu/

Laboratory link : https://iramis.cea.fr/LIDYL/DICO/

More : https://iramis.cea.fr/LIDYL/Phocea/Page/index.php?id=103&ref=99

High order laser harmonic generation in crystals is a new promising source of ultrashort coherent radiation in the extreme ultraviolet spectral domain (50-150 nm). The aim of this PhD work is to use the recent progress of the nano-manufacturing technologies in order to shape the emitting face of the non linear medium to manipulate the spatio-temporal properties of the radiation. Transposing the methods developed for linear meta-optics in the visible range to the strong field interaction regime, the student will extend their control abilities to a very large spectral bandwidth, in order to generate attosecond pulses shaped on demand.
Attosecond spectroscopy of molecules in gas and liquid phase

SL-DRF-23-0366

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Hugo MARROUX

Pascal SALIERES

Starting date : 01-10-2023

Contact :

Hugo MARROUX
CEA - DRF/IRAMIS/LIDyL/ATTO

0169081744

Thesis supervisor :

Pascal SALIERES
CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Personal web page : https://iramis.cea.fr/Pisp/pascal.salieres/

Laboratory link : http://iramis.cea.fr/LIDYL/

More : http://attolab.fr/

Summary :

The student will use attosecond laser techniques to study ultrafast dynamics of molecules in liquid and gas phase. Inner level attosecond photoionization will be used to study in real time: scattering/rearrangement/transfer electron dynamics, as well as solvation effects.



Detailed summary :

In recent years, the generation of sub-femtosecond pulses, known as attoseconds (1 as=10-18 s), has made spectacular progress. These ultrashort pulses open new perspectives for the exploration of matter on a timescale that was previously inaccessible. Their generation is based on the strong non-linear interaction of short (~20 femtoseconds) and intense infrared (IR) laser pulses with atomic or molecular gases. This produces high order harmonics of the fundamental frequency, over a wide spectral range (160-10 nm) covering the extreme ultraviolet (XUV). This high-energy radiation is able to ionize molecules by removing inner-layer electrons. In the time domain, this coherent radiation appears as pulses of ~100 attoseconds duration [1].



With these attosecond pulses, it becomes possible to study the fastest dynamics in matter, those associated with electrons, which naturally occur on this timescale. Attosecond spectroscopy thus allows the study of fundamental processes such as photoionization and addresses questions such as : How long does it take to pull an electron out of an atom or molecule? How does the electron cloud rearrange? These questions have become hot topics in the scientific community but have so far been studied in isolated systems, in the gas phase [2,3]. Advanced sampling technologies now allow us to study these electronic dynamics in a solvated medium where the behavior of electrons on these attosecond timescales is unknown. What energy or electron transfers take place in 10-18 second? Can we measure electron scattering effects in a liquid? These questions are a new challenge for our field on the experimental and theoretical level.



The objective of this thesis is first to implement attosecond techniques established in gas phase to the liquid phase. Two complementary detections will be used, photoelectron detection and transient absorption. By combining the information obtained by each technique, we will be able to measure the scattering of the photoelectron after its creation but also the fate of the ionized molecule: rearrangements/electron transfers, solvation effects.



The experimental work will include the development and the implementation of a beamline, installed on the FAB100 laser of the ATTOLab Excellence Equipment, allowing: i) the generation of attosecond radiation; ii) its characterization by quantum interferometry; iii) its use in photoionization and absorption spectroscopy. Theoretical aspects will also be developed. The student will be trained in ultrafast optics, atomic and molecular physics, quantum chemistry, and will acquire a broad mastery of XUV and charged particle spectroscopy techniques. Knowledge in optics, nonlinear optics, atomic and molecular physics is a prerequisite.

The thesis work could lead to experimental campaigns in French and associated European laboratories (Hamburg-DESY).



References :

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

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

[3] A. Autuori, et al., Science Advances 8, eabl7594 (2022)



Semi/Super-conducting Terahertz plasmonics

SL-DRF-23-0455

Research field : Radiation-matter interactions
Location :

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Yannis Laplace

Luca PERFETTI

Starting date : 01-10-2023

Contact :

Yannis Laplace
Ecole Polytechnique - Laboratoire des Solides Irradiés LSI - UMR 7642

0169334512

Thesis supervisor :

Luca PERFETTI
Ecole Polytechnique - Laboratoire des Solides Irradiés LSI - UMR 7642

01 69 35 81 42

Personal web page : https://www.polytechnique.edu/annuaire/laplace-yannis

Laboratory link : https://portail.polytechnique.edu/lsi/fr/recherche/nouveaux-etats-electroniques/terax-lab

More : https://www.polytechnique.edu/annuaire/perfetti-luca

Scientific and technological development of the Terahertz (THz) frequency range, a domain of the electromagnetic spectrum that is located in between microwaves and infrared photonics, is timely and subjected to an intense research activity recently. The aim of this PhD project will be to design and study plasmonic systems, principally plasmonic resonators, working at THz frequencies and capable of achieving tuneable, nonlinear and ultra-strong light-matter interaction at these frequencies. Contrary to other approaches previously developed, the candidate will achieve this with condensed matter systems that have an intrinsic plasmonic response in the THz frequency range, such as high-Tc superconductors and doped semi-conductors.
Phase separation of polyelectrolytes: fundamental aspects and application to membranes

SL-DRF-23-0742

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

Starting date : 01-11-2023

Contact :

Patrick GUENOUN
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Thesis supervisor :

Patrick GUENOUN
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Personal web page : https://iramis.cea.fr/Pisp/patrick.guenoun/index.html

Laboratory link : https://iramis.cea.fr/nimbe/lions/

The project is experimental and focuses on the study of new families of polyelectrolytes (PE) by determining their phase diagrams as a function of variations in temperature, added salt or pH. This will be done optically (microscopy, diffusion) at CEA Saclay. Once the diagrams have been established, the phase separation (PS) of the PE solutions will be studied by confocal fluorescence microscopy to determine the growth laws and the scaling behavior of the separation. Phase separation is a dynamic process that will be initiated by temperature or concentration quenches, followed by the acquisition of time series images or correlation functions. It will lead to the formation of spatial structures that will be used to achieve an interconnected porous geometry. The results will be translated into guidelines for membrane manufacturing procedures that will be applied in Montpellier (European Institute of Membranes) to manufacture porous polyimide membranes of high mechanical and thermal resistance. Another side of the project will be to reproduce the experimental finding by a theoretical model able 1/ to explain the measured phase diagrams, 2/ to complete existing phase field theories for phase separation of neutral polymers to describe PE phase separation.
Therapeutical lipidic nanoassemblies in a biomimetic medium: transformation, fate and interactions

SL-DRF-23-0369

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

Fabienne TESTARD

Starting date : 01-10-2023

Contact :

Frédéric GOBEAUX
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 55 21

Thesis supervisor :

Fabienne TESTARD
CEA - DRF/IRAMIS/NIMBE/LIONS

01 69 08 96 42

Personal web page : https://iramis.cea.fr/nimbe/Phocea/Pisp/index.php?nom=frederic.gobeaux

Laboratory link : https://iramis.cea.fr/Pisp/lions/index.html

More : https://www.umr-cnrs8612.universite-paris-saclay.fr/presentation_pers.php?nom=lepetre

Giving a general view of the colloidal stability of nanoparticles in a biological environment remains difficult. This comes mainly from the complexity of biological environments and the diversity of nanoparticles in terms of size distribution, shape, nature of external surface and nanostructure. In particular, the number of physico-chemical studies on “soft” organic particles obtained by self-assembly of bioconjugates remains low. To understand how the physico-chemical characteristics of "soft" nanoparticles direct their interactions with blood proteins, we propose, in collaboration with the Institut Galien, to study a concrete case where the nanostructure and the surface charge of the nanoparticles give different pharmacologically efficiency (analgesic). The objective is to study in detail how nanoparticles formed by self-assembly of bioconjugates interact with a model biological medium, taking into account both the main components (albumin, hemoglobin and lipoproteins) and the hydrodynamic flow from the circulation blood.
Thermoelectric energy conversion in ferrolfuids for hybrid solar heat collector

SL-DRF-23-0399

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 : 01-10-2021

Contact :

Sawako NAKAMAE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Thesis supervisor :

Sawako NAKAMAE
CEA - DRF/IRAMIS/SPEC/SPHYNX

0169087538

Personal web page : http://iramis.cea.fr/spec/Phocea/Pisp/index.php?nom=sawako.nakamae

Laboratory link : http://iramis.cea.fr/spec/SPHYNX/

More : https://www.magenta-h2020.eu

Thermoelectric (TE) materials that are capable of converting heat into electricity have been considered as one possible solution to recover the low-grade waste-heat (from industrial waste-stream, motor engines, household electronic appliances or body-heat).



At SPHYNX, we explore thermoelectric effects in an entirely different class of materials, namely, complex fluids containing electrically charged nanoparticles that serve as both heat and electricity carriers. Unlike in solid materials, there are several inter-dependent TE effects taking place in liquids, resulting in Se values that are generally an order of magnitude larger that the semiconductor counterparts. Furthermore, these fluids are composed of Earth-abundant raw materials, making them attractive for future TE-materials that are low-cost and environmentally friendly. While the precise origins of high Seebeck coefficients in these fluids are still debated, our recent results indicate the decisive role played by the physico-chemical nature of particle-liquid interface.



The goal of the PhD project is two-fold. First, we will investigate the underlying laws of physics behind the thermoelectric potential and power generation and other associated phenomena in a special type of complex fluids, namely, ferrofluids (magnetic nanofluids). The results will be compared to their thermos-diffusive properties to be obtained through research collaboration actions. Second, the project aims to develop proof-of-concept hybrid solar-collector devices that are capable of co-generating heat and electricity.



The proposed research project is primarily experimental, involving thermos-electrical, thermal and electrochemical measurements; implementation of automated data acquisition system and analysis of the resulting data obtained. The notions of thermodynamics, fluid physics and engineering (device) physics, as well as hands-on knowledge of experimental device manipulation are needed. Basic knowledge of optics and electrochemistry is a plus. For motivated students, numerical simulations using commercial CFD software can also be envisaged.
Creation and use of a model database for the ab initio calculation of optical properties of materials

SL-DRF-23-0443

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 : 01-10-2023

Contact :

Lucia REINING
CNRS - LSI/Laboratoire des Solides Irradiés

0169334553

Thesis supervisor :

Lucia REINING
CNRS - LSI/Laboratoire des Solides Irradiés

0169334553

Personal web page : https://etsf.polytechnique.fr/People/Lucia

Laboratory link : https://etsf.polytechnique.fr

More : https://portail.polytechnique.edu/lsi/fr/recherche/spectroscopie-theorique

This project aims at a clever re-use of data in the calculation of electronic spectra. Ab initio calculations often do not take advantage of the data produced, or they use databases of real materials requiring a huge amount of data. We have proposed an approach called "connector theory" to overcome this problem. It consists in calculating with high accuracy, but once and for all, a given property (total energy, spectra,...) for a model system as a function of its parameters. These results are saved and can be used to determine the same property in many real materials. This requires the knowledge of a "connector", a prescription for choosing the right information from the model database, depending on the real material and on specific parameters, for example, a particular frequency or location. We have formulated the exact theory and proposed a strategy for systematically approximating the connectors. At this point, it is necessary to design the specific connectors for each property of interest.



In this thesis, the student will optimise a model and design a connector for the optical properties of low-dimensional materials. She/he will establish the model database that is needed for this application, and complete it with interpolations, for example with machine learning. This will allow extremely frugal calculations of optical properties.

Spin Orbit Torque smart magnetic sensing

SL-DRF-23-0653

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 : 01-10-2023

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

Personal web page : https://iramis.cea.fr/spec/Phocea/Pisp/index.php?nom=myriam.pannetier-lecoeur

Laboratory link : https://iramis.cea.fr/spec/LNO/

Spin electronics is a powerful physics based not only on charge but also on electron spin. Already widely used for hard disk drive read heads, it has been increasingly implemented for magnetic field sensing, due to its sensitivity, miniaturization and ease of integration into CMOS. Nevertheless, the design and properties of these sensors are so far fixed at the time of fabrication and cannot be modified during their lifetime. This thesis aims at studying new concepts of magnetic sensors, integrating spinorbitronics (exploiting spin orbit torque) as an additional degree of freedom for the design of the sensor, allowing to change its characteristics such as direction or sensitivity range, or to dynamically reduce the noise, during the life of the sensor, making it reconfigurable. This concept will bring a new generation of intelligent sensors, capable of being electrically reconfigured during their lifetime.



Detailed subject:

The goal of this thesis is to develop tunneling magnetoresistance (TMR) structures using spin orbit torque to electrically manipulate magnetization and pave the way for reconfigurable magnetic sensors.

Magnetic sensors allow to measure both the magnetic field but also associated quantities, such as current or even the position of an object. They are more and more present in technological objects, as well as in the automotive and medical fields.

Spin electronics, whose experimental demonstration was crowned by the Nobel Prize in Physics in 2007 (A. Fert and P. Grünberg), has opened up important avenues of improvement for magnetic sensors thanks to the sensitivity and miniaturization of the basic elements.

However, a current limitation comes from the fact that the sensor is defined at the time of its manufacture and that its characteristics (such as the range, the sensitivity direction...) are thus fixed at the beginning. Thanks to the spin orbit torque (SOT) phenomenon, which consists in applying a magnetic force through a flow of spin-polarized electrons, it is possible to implement in a spintronics element a function of manipulation of some of the magnetic layers, and thus to imagine a sensor which can adapt itself during its use thanks to the reconfiguration of its references.

The thesis project will consist in developing Tunnel Magneto-Resistance (TMR) systems integrating a level of SOT to drive the sensor response, to fabricate the devices, test their performances and apply them in realistic environment for current sensing and magnetometry. This thesis will be part of the ANR-funded STORM project (starting in December 2022), in collaboration with UMPhy Thales and Crivasense Technologies. It will include the deposition of materials, their characterization in terms of SOT performance, then the realization of devices by microfabrication techniques, and magneto-transport measurements to evaluate the response of the sensors.

Local magnetic microscopy by integration of magnetoresistive sensors

SL-DRF-23-0423

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 : 01-10-2023

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

Personal web page : http://iramis.cea.fr/Pisp/aurelie.solignac/

Laboratory link : http://iramis.cea.fr/spec/LNO/

An ultrasensitive and quantitative magnetic microscope has been developed at the Nanomagnetism and Oxides Laboratory by combining an Atomic Force Microscope (AFM) scanning probe microscope and a magnetoresistive (MR) sensor integrated in an AFM cantilever. During this thesis, the aim is to investigate innovative applications of this microscope by using a specific property of MR sensors: their wide detection frequency range from DC to several hundred MHz or even GHz. Thus, the magnetic susceptibility properties of magnetic particles/materials can be studied, in particular in the context of the use of magnetic petals for stealth/RF absorption applications or of nanocrystal ribbons for electrical conversion applications. A second application is magnonics or the use of spin waves (rather than charges) to transport and process information with minimal energy loss. During the thesis, the integrated sensors will be developed and characterized, the microscope and the sensor electronics will be adapted to high frequency measurements. Another aspect of this thesis will be to be able to determine the magnetic properties of the studied materials from the measured field maps.



CVD synthesis of tailored nanodiamonds

SL-DRF-23-0347

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

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

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Hugues GIRARD

Jean-Charles ARNAULT

Starting date : 01-10-2023

Contact :

Hugues GIRARD
CEA - DRF/IRAMIS/NIMBE/LEDNA

0169084760

Thesis supervisor :

Jean-Charles ARNAULT
CEA - DRF/IRAMIS/NIMBE/LEDNA

01 68 08 71 02

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=hgirard

Laboratory link : https://iramis.cea.fr/NIMBE/LEDNA/

Diamond nanoparticles behave outstanding chemical, electronic, thermal and optical properties. Such nanoparticles are actively investigated for nanomedecine, energy applications, quantum technologies and advanced lubricants and composites [1-3]. For the major part of these applications, the crystalline quality of the diamond core is essential and the most studied particles are milled from bulk diamond. Nevertheless, these particles exhibit a wide size dispersion, shape anisotropies and variable concentrations of chemical impurities. These aspects strongly affect their properties. It is thus required to develop a synthesis method to grow highly crystalline nanodiamonds with an accurate control of their size, morphology and chemical impurities.

This PhD aims to develop a bottom-up synthesis based on sacrificial templates (silica beads or fibers) on which nanometric diamond seeds will be attached via electrostatic interactions. Diamond growth will be achieved by an exposure of the seeded templates to a micro-wave assisted CVD plasma (MPCVD). The growth set-up is already in use at CEA NIMBE for diamond core-shells synthesis [4]. Growth parameters will be adjusted to select the size, the shape and the concentration of chemical impurities (nitrogen, boron) in nanodiamonds. After CVD growth, nanoparticles will be collected by dissolution of the templates. Their crystalline structure, morphology and surface chemistry will be characterized at CEA NIMBE by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman, infra-red (FTIR) and photoelectrons (XPS) spectroscopies. An external collaboration will allow an investigation of the diamond crystalline quality and the identification of structural defects in CVD grown nanodiamonds by high-resolution transmission electron microscopy (HR-TEM).

Several kinds of nanodiamonds will be grown : first, intrinsic particles (without intentional doping), then boron doped particles. Both types of particles will be then surface modified to get a colloidal stability in water. Photocatalytic performances will be measured in collaboration with ICPEES (Strasbourg University). This original synthesis method will also permit to create colored centers (nitrogen-vacancy or silicon-vacancy) in nanodiamonds to exploit their optical properties (collaboration to initiate).



Références :



[1] N. Nunn, M. Torelli, G. McGuire, O. Shenderova, Current Opinion in Solid State and Materials Science, 21 (2017) 1-9.

[2] Y. Wu, F. Jelezko, M. Plenio,T. Weil, Angew. Chem. Int. Ed. 55 (2016) 6586–6598.

[3] H. Wang, Y. Cui, Energy Applications 1 (2019) 13-18.

[4] A. Venerosy et al., Diam. Relat. Mater. 89 (2018) 122-131.

Stress corrosion behavior of mesostructured glass by phase separation

SL-DRF-23-0356

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

Service de Physique de l’Etat Condensé (SPEC)

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

Saclay

Contact :

Laure CHOMAT

Cindy ROUNTREE

Starting date : 01-10-2023

Contact :

Laure CHOMAT
CEA - DRF/IRAMIS/SPEC/SPHYNX

01.69.08.30.42

Thesis supervisor :

Cindy ROUNTREE
CEA - DRF/IRAMIS/SPEC/SPHYNX

+33 1 69 08 26 55

Personal web page : https://iramis.cea.fr/Pisp/cindy.rountree/

Laboratory link : https://iramis.cea.fr/spec/SPHYNX/

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

Glass is a widely used material due to its many advantageous properties: transparency, hardness, low thermal expansion, high melting point temperature, relative chemical inertia, etc. However, it has one major weakness: its fragility. Relatively moderate stresses can cause it to break suddenly and without any warning. Glass is also sensitive to stress corrosion cracking: sub-crtical cracking aided by environmental conditions (relative humidity, temperature, etc.). In this case, apparently harmless stresses (much lower than those leading to its sudden breakage) can lead to crack propagation at low rates, as observed in the slow cracking of car windscreens. This stress corrosion cracking (SCC) also depends on the intrinsic parameters of the glass: chemical composition, microstructure, etc.



The phenomenon of phase separation in glasses leads to a meso-structured material which can improve mechanical properties such as crush resistance. It is also at the origin of glass-ceramics, consisting of microcrystals dispersed in a glass matrix, developed to take advantage of the benefits of both components: ceramics and glasses. They are used, for example in optical thermometry applications, kitchen utensils, dental materials, etc. However, the stress corrosion behavior of this type of material is still poorly understood.



The objective of this project is to study the link between the meso-structure of glass-ceramics and their stress corrosion cracking behavior. Samples will concern as fabricated samples and their phased separated counterparts which will be achieved by varying annealing protocols. The candidate will make use of an existing SCC experimental set-up allowing experiments in well controlled conditions (Figure 1 top). The rate of crack propagation and its variation with applied stress will be measured for each samples to obtain the characteristic stress corrosion resistance curves. In parallel, the composition and meso-structure of the samples will be studied using different techniques: AFM, SEM, Raman, etc. The candidate will also use a state-of-the-art Atomic Force Microscope (AFM) to characterize post-mortem fracture surfaces. These studies will aid in characterizing the size of phase separation and will feed different statistical tools (stochastic modelling, fractal analysis).



This internship will take place in the SPHYNX lab located in the Condensed State Physics Service which is a joint CEA / CNRS unit (UMR 3680 CEA-CNRS). Researchers study condensed matter physics, from the most fundamental physics to industrial applications. The candidate will have the opportunity to use and learn first-hand advanced methods for characterizing materials and their surfaces, from the macroscopic to the nanometric scale. The approaches will be based on experimental platforms and theoretical tools developed in-house. The candidate will have the opportunity to manipulate theoretical and experimental tools used in the field of materials science, mechanics and statistical physics. Finally, the very fundamental and applied character of this research will allow the candidate to find opportunities in the academic world (thesis) and in industry.
Ising garnet hyperkagome networks for enhanced magnetocaloric effect

SL-DRF-23-0333

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

Laboratoire Léon Brillouin (LLB)

Groupe Diffraction Poudres (GDP)

Saclay

Contact :

Françoise DAMAY-ROWE

Starting date : 01-10-2023

Contact :

Françoise DAMAY-ROWE
CNRS-UMR 12 - LLB - Laboratoire de Diffusion Neutronique

01 69 08 49 54

Thesis supervisor :

Françoise DAMAY-ROWE
CNRS-UMR 12 - LLB - Laboratoire de Diffusion Neutronique

01 69 08 49 54

Personal web page : https://iramis.cea.fr/Pisp/francoise.damay/

Laboratory link : https://iramis.cea.fr/llb/NFMQ/

Alternate coolants are needed to replace the use of increasingly scarce liquid helium, required, for instance, to cool the superconducting magnets used in medical resonance imaging. Magnetocaloric materials, with their entropically driven cooling power when cycled in a magnetic field, are such a replacement. The gadolinium-based garnets developed recently show amongst the largest magnetocaloric effects ; yet the cooling power of those materials peaks below 2 K, too low for many applications of liquid helium.



The aim of this PhD project is to find new rare-earth garnets with better magnetocaloric performances, by adequate substitutions on the three available cationic sites of the garnet structure. The project originality is the investigation of high-entropy garnet oxides to achieve this goal. The use of neutron scattering techniques will be a key asset to correlate chemical substitutions with changes in magnetic anisotropy and ground states in applied magnetic field, for an in-depth understanding of the key parameters controlling the magneto-caloric effect.
Study of loop currents state in cuprates

SL-DRF-23-0075

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

Laboratoire Léon Brillouin (LLB)

Groupe 3 Axes (G3A)

Saclay

Contact :

Philippe Bourges

Starting date : 01-09-2023

Contact :

Philippe Bourges
CEA - DRF/IRAMIS/LLB/G3A

0169086831

Thesis supervisor :

Philippe Bourges
CEA - DRF/IRAMIS/LLB/G3A

0169086831

Personal web page : https://iramis.cea.fr/Pisp/113/philippe.bourges.html

Laboratory link : https://www-llb.cea.fr/NFMQ/

For a decade, several experimental techniques has provided compelling evidence in favor of an intra-unit-cell (IUC) state of matter in the pseudo-gap state of 2D high temperature superconducting cuprates and iridates, and more recently in doped 2-leg ladder cuprates [1]. This state breaks time reversal and inversion symmetries, but preserves the lattice translation invariance. All these experimental observations could be the hallmarks of a magneto-electric state of matter that could take the form of either a loop current order [2] or a quadrupole order [3]. The loop currents are bound to toroidal moments (or anapoles), similar to those discussed in different multiferroic compounds. Recently, using polarized neutron diffraction techniques, we revealed novel magnetic correlations that yield either a doubling or quadrupling of the magnetic unit cell [4]. The magnetic moments are mainly pointing perpendicular to the CuO2 layers as expected for loop currents. This new magnetism together with the IUC magnetism previously reported, yields a hidden magnetic texture of CuO2 unit cells hosting loop currents.



In order to get a deeper insight in the intrinsic nature of the exotic magnetism, we propose to use polarized resonant X-ray diffraction (RXD) technique. The polarization analysis is a powerful tool as it allows a selective identification of the anapole and quadrupole terms. Indeed, although associated with multipolar orders, loop currents and quadrupoles state imply very distinct electronic distributions and microscopic origins. While a loop current delocalizes on several atoms, a quadrupole is localized on a single atom [3]. In addition to the RXD measurements, polarized neutron diffraction will be use for the study the phase diagram of several copper oxides materials that include high-temperature superconductors (YBa2Cu3O7-d, HgBa2CuO4+d, (Sr,Ca)14Cu24O41,CuO, etc). The RXD experiments will mainly be carried on the I16 beamline of the Diamond Light Source (U.K.) and the ID32, XMaS beamlines at ESRF. The neutron diffraction at Institut Laue Langevin (ILL) Grenoble.



To perform this research program, we propose a PhD program at Laboratoire Léon Brillouin (LLB-Saclay) in close collaboration with the Laboratoire de la Physique du Solide (LPS-Orsay), both localized at the University Paris-Saclay

References



[1] P. Bourges, D. Bounoua, Y. Sidis, C. R. Phys. 22, 1–25 https://doi.org/10.5802/crphys.84 (2021).

[2] C. Varma, Phys. Rev. B 73, 155113 (2006); M. S. Scheurer and S. Sachdev, Phys. Rev. B 98, 235126 (2018). S. Sarkar et al., Phys. Rev. B 100, 214519 (2019).

[3] M. Fechner et al., Phys. Rev. B 93, 174419 (2016); S. W. Lovesey and D. D. Khalyavin, J. Phys. Condens. Matter 29, 215603 (2017).

[4] D. Bounoua et al, accepted in Comms. Phys. (2022), https://arxiv.org/abs/2111.00525
Photoinduced plasmon satellites

SL-DRF-23-0444

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

Laboratoire des Solides Irradiés (LSI)

Laboratoire des Solides Irradiés (LSI)

Saclay

Contact :

Matteo GATTI

Lucia REINING

Starting date : 01-10-2023

Contact :

Matteo GATTI
CNRS - LSI

0169334538

Thesis supervisor :

Lucia REINING
CNRS - LSI/Laboratoire des Solides Irradiés

0169334553

Personal web page : https://etsf.polytechnique.fr/People/Matteo

Laboratory link : https://etsf.polytechnique.fr

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

Photoemission spectroscopy is one of the most direct ways to access the electronic structure of materials. Chasing the dream of controlling matter with light and creating new functionalities on demand, the advent of free electron laser sources is opening up new exciting opportunities for time-resolved spectroscopies of materials. In order to turn these high hopes into reality, a deeper understanding of the photoinduced change of materials properties out of equilibrium is the first compelling priority. The thesis project addresses this challenge by disclosing genuine signatures of electron correlation in time-resolved photoemission spectra and enabling the full use of their physical information. The main peaks usually correspond to the quasiparticle band structure. Replicas of these peaks, called satellites, are entirely due to interactions. They cannot, by definition, be interpreted from a single-particle point of view and, therefore, carry information complementary to the insight gained from the band structure. They reflect the strength of electronic correlation in a material, and they feature length-and time-scales that differ from those of the quasiparticles. However, the satellite part of the spectra is in general much less studied than the quasipartcles. The photoexcitation of carriers can be interpreted as a photodoping process that changes the screening properties of materials. We expect that photoexcitation can affect the satellites even more strongly than the quasiparticles: satellites could be used as a diagnostic tool informing on the effect of the laser excitation with enhanced sensitivity than the quasiparticles alone.



Hafnium Oxide Ferroelectric Films: from fundamental understanding to optimized, low power device integration

SL-DRF-23-0332

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 :

NiCK BARRETT

Starting date : 01-10-2023

Contact :

NiCK BARRETT
CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Thesis supervisor :

NiCK BARRETT
CEA - DRF/IRAMIS/SPEC/LENSIS

0169083272

Personal web page : https://iramis.cea.fr/Pisp/nick.barrett/

Laboratory link : https://iramis.cea.fr/SPEC/LENSIS/

More : https://www.lensislab.com/

Ferroelectricity in doped HfO2 thin films under appropriate strain and annealing conditions was reported for the first time 10 years ago generating strong interest in the non-volatile memory community.



Thanks to CMOS compatibility and potential for scaling and 3D integration, it is not only a breakthrough with respect to conventional perovskite-based ferroelectric (FE) devices but also a revolution from an application prospective.



Compared to technologies like Flash or resistive or phase changememories, FE memories are intrinsically low power: reversing the electrical polarization which encodes the information is three orders of magnitude more energy efficient than the nearest competitors.



However, increasing the technological maturity requires understanding the influence of dopants and defects on device performance.



We will use advanced operando materials characterization to trace a path for device optimization by fundamental materials engineering.
Oxygen evolution reaction at the interface between a semiconducting metal oxides and aqueous electrolyte during solar water splitting reaction

SL-DRF-23-0751

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 :

Dana STANESCU

Yannick DAPPE

Starting date : 01-10-2023

Contact :

Dana STANESCU
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 75 48

Thesis supervisor :

Yannick DAPPE
CNRS - DRF/IRAMIS/SPEC/GMT

+33 (0)1 69 08 84 46

Personal web page : https://iramis.cea.fr/Pisp/dana.stanescu/

Laboratory link : https://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast_visu.php?id_ast=2977

The aim of the PhD is to understand and describe the mechanisms underlying the OER during SWS reaction by realizing a comparative study both for co-catalyst modified a-Fe2O3 and BiVO4 photoanodes. This thesis work will be articulated around several axes: i) synthesis of photoanodes by chemical methods on two types of substrates (FTO and glassy carbon); ii) macroscopic photoelectrochemistry characterization: photocurrent and direct hydrogen quantification, electrochemical impedance spectroscopy; iii) synchrotron based characterization using ex situ spectromicroscopies (STXM and XPEEM using NEXAFS contrast) at SOLEIL synchrotron (HERMES beamline). This analysis will provide direct information on the chemical composition and homogeneity, morphology and electronic structures of photoanodes. iv) DFT methods using existing codes that will allow dissecting fine NEXAFS features from STXM and XPEEM data. Additionally, DFT calculations will predict different material electronic structures of interest through atomic structure optimization, and consequently, the potential reactivity related to electronic level alignments. The student will be hosted by SPEC laboratory at CEA-Saclay for the entire thesis.
Orbital/Charge interconversion in 2D electron gazes

SL-DRF-23-0411

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 :

Michel VIRET

Starting date : 01-09-2023

Contact :

Michel VIRET
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Thesis supervisor :

Michel VIRET
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Personal web page : https://iramis.cea.fr/Pisp/michel.viret/

Laboratory link : https://iramis.cea.fr/SPEC/LNO/

The Rashba effect is well known in the community of researchers working on two-dimensional electron gases, and especially in spintronics as the chiral spin coupling of the band structure is used to inter-convert spin and charge. In some materials, it appears that the orbital effects are much larger than those of the spins. We have just demonstrated that this is indeed the case in the LaAlO3/SrTiO3 system. It is now necessary to study the effect of the thickness of the LaAlO3 barrier and of the angular dependencies. It is also important to study these phenomena at the picosecond time-scale, which is possible in our laboratory using ultra-fast lasers to produce pure picosecond spin pulses. For the proposed subject, the selected student will perform low-temperature measurements on time scales ranging from DC (spin Seebeck) to picosecond (ultra-fast demagnetization) on state-of-the-art LAO/STO samples from the University of Geneva. The work will be extended to other possible systems like Cu/CuO synthsized in our laboratory.
Influence of a nano-antenna on the intersystem crossing rate of a single molecule

SL-DRF-23-0438

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 :

Simon VASSANT

Fabrice CHARRA

Starting date : 01-10-2023

Contact :

Simon VASSANT
CEA - DRF/IRAMIS

+33 169 089 597

Thesis supervisor :

Fabrice CHARRA
CEA - DRF/IRAMIS

+33/169089722

Personal web page : https://iramis.cea.fr/Pisp/simon.vassant/

Laboratory link : https://iramis.cea.fr/spec/LEPO/

Within the framework of the ANR JCJC PlasmonISC project, we propose a thesis subject mainly experimental in nano-photonics. The objective of the thesis is to study the influence of a nano-antenna (plasmonic, magnetic or dielectric) on the rate governing the photophysics of fluorescence emission from a single molecule, with a particular interest in the intersystem crossing rate. We have developed a dedicated optical bench combining optical and atomic force microscopy, an experimental procedure, as well as signal processing tools, showing encouraging first results with a dielectric tip. We wish to continue to explore the single molecule/nano-antenna interaction with other types of tips generating other physical effects. The ability to control the transition to the triplet state is of great interest for single photon sources, organic light emitting diodes, and in chemistry.
Simulating and imaging nanostructured magneto-electric chiral antiferromagnets

SL-DRF-23-0419

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-yves Chauleau

Michel VIRET

Starting date : 01-09-2023

Contact :

jean-yves Chauleau
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 72 17

Thesis supervisor :

Michel VIRET
CEA - DRF/IRAMIS/SPEC/LNO

01 69 08 71 60

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=jchaulea

Laboratory link : https://iramis.cea.fr/SPEC/LNO/

BiFeO3 is a very particular material because it has two coupled orders: an electrical polarization and an antiferromagnetic order. The magneto-electric coupling gives it a complex, chiral magnetic configuration, which can be seen at the synchrotron or with a suitable local probe such as imaging using the NV center of diamond. At the CEA, we have also developed a very flexible simulation code that allows us to predict the magnetic properties of strained electrically polarized BiFeO3 (nano)structures, with the aim of producing antiferromagnetic ‘skyrmions’. The goal of the thesis will be to simulate some already made structures and to imagine others. Also, the student will use a near-field microscope, under development in the laboratory, to attempt to measure the predicted configurations in samples of BiFeO3 synthesized at UMR CNRS/Thales.
From Theoretical Spectroscopy to Materials Properties

SL-DRF-23-0447

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 : 01-10-2023

Contact :

Francesco SOTTILE
Ecole Polytechnique - UMR 7642

0169334549

Thesis supervisor :

Francesco SOTTILE
Ecole Polytechnique - UMR 7642

0169334549

Personal web page : https://etsf.polytechnique.fr/People/Francesco

Laboratory link : https://etsf.polytechnique.fr

The computational design of materials is gaining broad recognition as an effective mean of reducing the number of experiments that can ultimately lead to the discovery of materials with tailored properties. Spectroscopy, by probing the response of materials to external perturbations, allows the analysis of the induced elementary excitations and hence characterisation of the material properties. There are many kinds of experimental techniques, each with its own capabilities, advantages and drawbacks, and with its more or less efficient theoretical counterpart. Scope of this thesis is give a unified view on different spectroscopy, via the fundamental concept of electron screening. With the help of theoretical and numerical developments within Green's functions theory, we plan to describe, analyse and predict optical and electronic properties of a wide range of materials, from model-like systems to vanadates, from oxides to oxalates. This thesis project, while heavily based on theoretical and numerical developments, has also a strong connection to experiments.

Controlling phase separation in active systems

SL-DRF-23-0341

Research field : Theoretical Physics
Location :

Service de Physique de l’Etat Condensé (SPEC)

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

Saclay

Contact :

Cesare Nardini

Starting date : 01-09-2023

Contact :

Cesare Nardini
CEA - DRF/IRAMIS/SPEC/SPHYNX


Thesis supervisor :

Cesare Nardini
CEA - DRF/IRAMIS/SPEC/SPHYNX


Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=cnardini

Laboratory link : https://iramis.cea.fr/SPEC/SPHYNX/

More : https://scholar.google.com/citations?user=F5AitakAAAAJ&hl=en

Examples of active systems, formed of units that are able to extract energy from the environment and dissipate it to self-propel, are found everywhere in nature: flocks of birds, animal swarms, suspensions of bacteria or tissues are all biological active systems. Scientists are able to build synthetic active systems using catalytic colloidal particles or micro-robots.

Future applications may encompass the engineering self-assembling materials using active units, considered as a defining agenda in the community. Furthermore, active systems have theoretically fascinating properties, a fact that drove a very intense research activity lately.



Large assemblies of active units display collective phenomena that are absent in equilibrium. One of the most ubiquitous is phase separation, where even repulsive but active particles phase separate into dense and dilute phases. In some cases, this phenomena resemble to liquid-vapor phase separation of standard fluids. Due to broken time-reversibility, however, active systems can show novel forms of phase separation, comprising a state where the liquid state comprises mesoscopic vapor bubbles (thus resembling to a boiling liquid) or active foams states, where thin liquid filaments are dispersed in the vapor.

Furthermore, in most experimental realization, active systems are `wet’, meaning that particles move in a fluid which itself can mediate interactions among particles, a feature whose consequences are so far little understood theoretically.



The main open theoretical question is how to control these novel states of matter in terms of microscopically tunable parameters. The main goal of this PhD is to fill this gap. This will require both analytical and computational work done on agent based models and continuous descriptions of active systems. If successful, the work will provide a guide for experimentalists to design novel self-assembling materials using active units. Given the ubiquity of phase separation in non-equilibrium contexts, we will further explore the relevance of these results to other out-of-equilibrium systems, such as biological tissues and granular materials.
Many-body physics of topological defects in active materials

SL-DRF-23-0342

Research field : Theoretical Physics
Location :

Service de Physique de l’Etat Condensé (SPEC)

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

Saclay

Contact :

Cesare Nardini

Starting date : 01-09-2023

Contact :

Cesare Nardini
CEA - DRF/IRAMIS/SPEC/SPHYNX


Thesis supervisor :

Cesare Nardini
CEA - DRF/IRAMIS/SPEC/SPHYNX


Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=cnardini

Laboratory link : https://iramis.cea.fr/SPEC/SPHYNX

More : https://scholar.google.com/citations?user=F5AitakAAAAJ&hl=en

Many space-time features of biological and active materials, from morphogenesis to the structure of dense assemblies of self-propelled colloids, are caused and controlled by topological defects. These can be defects on top of liquid-crystalline orders such as nematics or hexatics, or even on top of a crystalline solid. Defects can mediate anomalous stress propagation, shape the curvature of the underlying flexible materials, or even cause phase transitions between states where defects are bounded to ones where they can freely diffuse.



This PhD project aims at understanding the many-body physics of topological defects in active materials with a combination of analytical and numerical techniques, and at exploring their relevance for collective phenomena in active and living systems.
Investigating the Evolving Chemistry and Crystallography of Sustainable Cements During Their Carbonation

SL-DRF-23-0407

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 :

Mark LEVENSTEIN

Corinne CHEVALLARD

Starting date : 01-10-2023

Contact :

Mark LEVENSTEIN
CEA - DRF/IRAMIS/NIMBE/LIONS

+33 (0) 1 69 08 57 34

Thesis supervisor :

Corinne CHEVALLARD
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-54-89

Personal web page : https://www.researchgate.net/profile/Mark-Levenstein-3

Laboratory link : https://iramis.cea.fr/Pisp/lions/index.html

More : https://www.researchgate.net/profile/Stephane-Poyet/

This PhD subject is focused on evaluating novel cement and mortar formulations comprising repurposed industrial slags, ashes, and lightly-processed raw minerals as more sustainable alternatives to Ordinary Portland Cement (OPC). These formulations will be optimized to facilitate the setting and strengthening of concrete via carbonation rather than hydration, which has the potential to reduce even further the emissions of concrete towards net carbon capture and storage (CCS). The carbonation mechanisms of the different formulations under different environmental conditions (temperature, relative humidity, %CO2) will be elucidated in situ using a variety of techniques including micro X-ray diffraction (XRD) and X-ray micro computed tomography (µ-CT). We will also further develop recently-introduced methods in digital pH imaging to understand the evolving chemical environment in and around the cement as it matures. Cement and mortar formulations will be characterized across a number of length and time scales utilizing microfluidic devices up to full-scale carbonation cabinets and utilizing laboratory X-ray sources up to synchrotron radiation facilities.
Capture of atmospheric CO2 with nanofluids

SL-DRF-23-0067

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 :

Christophe FAJOLLES

David CARRIÈRE

Starting date : 01-10-2021

Contact :

Christophe FAJOLLES
CEA - DSM/IRAMIS/NIMBE/LIONS

01 69 08 99 60

Thesis supervisor :

David CARRIÈRE
CEA - DRF/IRAMIS/NIMBE/LIONS

0169085489

Personal web page : http://iramis.cea.fr/Pisp/david.carriere/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

More : https://iramis.cea.fr/Pisp/christophe.fajolles/

One of the ways strongly encouraged by the IPCC (Intergovernmental Panel on Climate Change) to mitigate climate change is the capture of CO2 by liquid amines, followed by the recovery of the gas and its deep underground storage. However, an essential problem makes the process currently inefficient: the recovery of CO2 must be done by heating and is too energy intensive.



In this context, this thesis will study how the addition of nanoparticles improves the recovery of CO2 from liquid amines. These “nanofluids” have proven efficacy, but there is little guidance on how to achieve an appropriate composition, and no consensus on the mechanism that would facilitate the release of CO2 gas.



The objective of this thesis is to propose rational guidelines, which will lead to the best nanoparticle + liquid amine combination, replacing the current trial-and-error approaches. It will therefore be necessary to study how the surface of nanoparticles 1) activates the chemical reaction of release, and 2) facilitates the physical process of nucleation of gas bubbles.
Protection of copper-based heritage metals by sol-gel treatments - understanding the physicochemical mechanisms of corrosion inhibition

SL-DRF-23-0416

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

Saclay

Contact :

Laurent MUGHERLI

Delphine Neff

Starting date : 01-10-2023

Contact :

Laurent MUGHERLI
CEA - Liste des pôles/Liste des départements/Liste des services/LEDNA

0169089427

Thesis supervisor :

Delphine Neff
CEA - DRF/IRAMIS/NIMBE/LAPA

01.69.08.33.40

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=lmugherl

Laboratory link : https://iramis.cea.fr/nimbe/ledna/

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

The proof of concept of the effectiveness of sol-gel coatings doped with carboxylic acid for the protection of copper-bearing heritage metals was demonstrated in a first PhD-thesis conducted within a NIMBE LAPA/LEDNA collaboration. In order to optimise the formulation of this coating on metals with a Corrosion Product Layer (CPL) of several tens of micrometres thickness that needs to be preserved, it is necessary to develop an in-depth study of the physico-chemical mechanisms of the protection. In this new thesis project, a multi-technique and multi-scale characterisation methodology will be implemented on old CPC samples as well as on model CPC samples. On the one hand, the formulation parameters (TMOS and/or TEOS precursors) will be adjusted to favour brush or spray application. On the other hand, the protection mechanisms will be studied through electrochemical measurements as well as through re-corrosion experiments in marked media (D2O/18O2, KBr under aggressive immersed conditions). The analytical protocol will be based on analyses at the global scale (viscosity, BET, mercury porosimetry, ATG, DRX), at the micrometric scale (SEM-EDS, Raman spectrometry) as well as at the nanometric scale (TEM on FIB slides) in order to understand the systems obtained during the treatments.
Vertically aligned carbon nanotubes based materials as a novel microporous layer structure for gas diffusion layer in PEMFC

SL-DRF-23-0046

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

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

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Mathieu PINAULT

Arnaud MORIN

Starting date : 01-12-2022

Contact :

Mathieu PINAULT
CEA - DRF/IRAMIS/NIMBE/LEDNA

01-69-08-91-87

Thesis supervisor :

Arnaud MORIN
CEA - DRT/DEHT//LCP

0438785986

Personal web page : https://iramis.cea.fr/Pisp/mathieu.pinault/

Laboratory link : https://iramis.cea.fr/nimbe/ledna/

This thesis work focuses on the development of a new microporous structure for PEMFC gas diffusion layers. The development of new materials for PEM fuel cells is a necessity to improve the power density provided by actual cell, to reduce the cost of materials and the price of the system. PEMFCs have problems with the distribution of liquid water inside the cell, particularly in its porous

layers. The microporous layer is one of the porous layers whose role is to optimize the water distribution. Developing a new micro-porous structure can provide additional information on the parameters influencing water management in the cell and provide a path to improving the fuel cell performance. As part of the PEPR (Priority Research Program and Equipment) H2 PEMFC95 project, the CEA Departments of IRAMIS (Saclay) and Hydrogen for Transport (LITEN-DEHT Grenoble) will collaborate on the development of Optimized and innovative GDLs based on carbon nanotubes, more suitable for the defined operating conditions. Aligned CNT mats have indeed demonstrated their effectiveness as a microporous layer [1]. The performance is at least similar to the best state-of-the-art gas diffusion layer depending on the conditions, and up to 30% improvement in power density could be achieved, without any hydrophobic treatment. For this thesis subject, we propose to continue the development of these diffusion layers integrating CNTs for their interest in terms of stability with respect to oxidation and their hydrophobicity by producing microporous layers with variable porosity. The objective is to substitute them for GDL while improving understanding of its role and, in general, of transport phenomena in a PEMFC core. To do this, the work has two parts. A materials section with manufacturing aspects and characterization of functional properties and an electrochemistry section with fuel cell measurements
Nanodiamond / TiO2 hybrids for green hydrogen production by photocatalysis

SL-DRF-23-0679

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

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

Laboratoire Edifices Nanométriques (LEDNA)

Saclay

Contact :

Hugues GIRARD

Starting date : 01-10-2023

Contact :

Hugues GIRARD
CEA - DRF/IRAMIS/NIMBE/LEDNA

0169084760

Thesis supervisor :

Hugues GIRARD
CEA - DRF/IRAMIS/NIMBE/LEDNA

0169084760

Personal web page : https://iramis.cea.fr/nimbe/Phocea/Membres/Annuaire/index.php?uid=hgirard

Laboratory link : https://iramis.cea.fr/nimbe/ledna/

H2 is a promising vector for solar fuels due to its high energetic content (142 kJ/mol) compared to fossil fuels. Efficient technologies for H2 production are still under investigation and storage and transportation need to be addressed.

This PhD aims to elaborate hybrids from ND and TiO2 toward H2 production by photoassisted water splitting under solar-light, following two different strategies: (i) by electrostatic adsorption (layer-by-layer approach) of the different ND and TiO2 materials dispersed in suspension; (ii) by introducing ND during the synthesis of TiO2 nanostructures. Post-synthesis treatments such as annealing in controlled atmospheres will also be considered to favor optimized TiO2/ND interfaces. ND of different crystalline quality (detonation, HPHT milled), shape (rounded, facetted) and size (from 5 to 150 nm) will be prepared with adequate surface chemistries (C-H, C-NH2, sp3/sp2) at CEA by well-established gas-phase annealing methods (under H2, NH3 or vacuum). ICPEES will provide TiO2 nanostructures of different crystalline structure (rutile/anatase), crystalline quality, morphology (nanoparticles, nanotubes) and size using tunable sol-gel and hydrothermal synthesis approach. The effect of surface pre-treatments on TiO2 PC efficiency will be investigated. The various photocatalysts will be characterized all along its development by SEM, HRTEM, XPS, FTIR, XRD, Raman. Then, performances of ND/TiO2 catalytic materials for H2 production by PC will be quantified at ICPEES by means of assessment of photocatalytic water-splitting under solar and visible light irradiation. Kinetics of H2 production will be followed as well as determination of quantum yields will be studied depending as a function of concentration of photocatalyst, nature and concentration of sacrificial agent and light irradiance.
Effect of substitution on ferroelectric and photocatalytic properties of barium titanates nanoparticles

SL-DRF-23-0743

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

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

Laboratoire d’étude des éléments légers (LEEL)

Saclay

Contact :

Yann LECONTE

Starting date : 01-10-2023

Contact :

Yann LECONTE
CEA - DRF/IRAMIS/NIMBE/LEEL

0169086496

Thesis supervisor :

Yann LECONTE
CEA - DRF/IRAMIS/NIMBE/LEEL

0169086496

Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=leconte

Laboratory link : https://iramis.cea.fr/NIMBE/LEEL/

In the context of the energy transition, the production of hydrogen from solar energy appears to be an extremely promising means of storing and then producing energy. The photoelectrolysis of water, to develop on a large scale, needs materials with high catalytic efficiency. Among the candidates considered, materials derived from barium titanates appear promising because their ferro- and piezoelectric properties could increase their photocatalytic effect.



We therefore propose in this subject, carried out in collaboration between the LEEL of the CEA and the SPMS of Centrale – Supelec, to synthesize BaTiO3 nanoparticles by flame spray pyrolysis with substitutions on Ba and O in order to study the effect of these modifications on the ferroelectric properties of the material. The addition of noble metal inclusions on the surface of the particles, likely to improve the catalysis, will also be carried out during the synthesis of the latter. Finally, photocatalysis and piezocatalysis tests will make it possible to establish the links between ferroelectric and catalytic phenomena in this family of materials.

 

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