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MesoXcope

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Project overview

 

The objective of this project is to make a groundbreaking contribution to fundamental research using X-ray spectromicroscopy on surfaces and interfaces of multiferroics materials for new energy technologies.

Spintronic appears as a fantastic alternative to CMOS technologies because of lower energy dissipation in magnetic processes. Multiferroicity, in which the magnetic state can be controlled by an electric field, is one promising solution for low consumption spintronic devices. Mastery, knowledge and optimization of magneto-electric materials from the atomic to the mesoscopic scale is therefore of great interest. Thus, spectroscopic and chemical analysis combined with spatial and temporal resolution to highlight correlations is an urgent requirement to better understand these materials. Fully energy filtered, high transmission photoelectron emission microscopy stimulated by X-rays (XPEEM) meets all these criteria.

With the MesoXcope, the simultaneous imaging of chemical and electronic structure in real and reciprocal space on a sub-micron scale becomes possible (Fig. 1).

Fig. 1. Schematic showing how the MesoXcope can image both chemical states in real space and electronic structure in reciprocal space, here the example is a polycrystalline Cu film.

The project, led by Nicolas Barrett of SPCSI (CEA) requires the acquisition and implementation of an innovative experimental apparatus, optimized for spectroscopic studies, called a MesoXcope. The excellent energy, spatial and wave vector resolution will also serve other research.

The initial research focus will be on materials showing novel electric, electronic and magnetic properties, often with high degrees of correlation such as photovoltaics, superconductors, ferroelectrics and multiferroics. This organization should stimulate complementary analyses using other state of the art techniques on the same systems. The ultimate potential of the MesoXcope will be realized by important synchrotron radiation campaigns with a priority given to the exploitation of the SOLEIL synchrotron.

Beamtime will thus be applied for via submission of experimental proposals to the relevant program committees. Thanks to measurement campaigns carried out using a prototype MesoXcope at the ESRF, BESSY, ELETTRA and SOLEIL, the partners have already considerable expertise in such operations, with an optimized installation uptime as short as 24 hours. We note that the extensive work with high intensity laboratory sources will be crucial for an optimum return on the synchrotron radiation experiments.

Fig. 2. 3D vision of the MesoXcope at the current stage showing both the main chamber and a fully equipped preparation chamber.

  • This advanced instrument (Fig. 2) will be one of the leaders in the field of MesoXcopy.
  • The combination of the MesoXcope and the existing SOLEIL XPEEM will give a spectromicroscopy facility second to none in the world.
  • The acquisition of intense laboratory sources and the exploitation of HHG lasers (PLFA) in the framework of the Attolab Equipex project will allow all year round international standard research to be conducted with the MesoXcope.
  • The high brilliance of the SOLEIL synchrotron radiation should allow the hitherto unattainable combination of 50 meV energy and 50 nm spatial resolutions in core level imaging to be achieved.
  • The skills of the present partners in the fabrication, electrical and magnetic characterization, and electronic and chemical structure analysis of multiferroics in the widest sense of the term, will create a powerful new local synergy in the study of these fascinating oxides. For example, recent collaborative work between two partners in the project, the SPCSI and the CNRS/Thalès joint laboratory, has allowed measurement of the ferroelectric polarization of ultra-thin BiFeO3 films by PEEM, a measurement hitherto impossible using standard electrical measurements because of leakage currents (Fig. 3).

Fig. 3. (left) Work function map of oppositely polarized ferroelectric domains in an ultrathin BiFeO3 film measured using a prototype MesoXcope. (right) Thickness dependence of the polarization as deduced from PEEM measurements.

 

  • The MesoXcope will be available for user experiments, managed under the responsibility of the scientific consortium using a public access system. As one example, we show the 3D band structure of the Dirac cones of few graphene grown epitaxially on silicon carbide, as measured with a prototype MesoXcope. This work demonstrated for the first time how the extremely weak coupling between adjacent graphene sheets can give rise to elastic scattering of the Dirac cones (Fig. 4).

Fig. 4. 3D representation of the Dirac cones from a 7 micron region of few layer graphene on the carbon face of SiC(0001). Work done in collaboration with Prof. E. Conrad, GeorgiaTech (Atlanta).

The MesoXcope will be operated by the scientific consortium, guaranteeing user access to a wide scientific community. User support for laboratory and synchrotron radiation based work will be provided by the MesoXcopy consortium. The researchers of major partner in the consortium will be the first beneficiaries of this user time. It will also provide a platform for educating young scientists in the use of the MesoXcope thus durably expanding the user community.

 

Information

Funding

  • Sesame - Equipement mi-lourds 2011
  • Triangle de la physique (Project 2011-022T)
  • LPMS - Universite de Cergy Pontoise, France
  • SPMS - ECP CNRS — DR Île-de-France Secteur Ouest et Nord
  • IFF-9/FZ Jülich, Germany
  • IRAMIS - CEA

Coordination

Specifications

  • Installation of the MesoXcope in the SPCSI : April 2013
 

Last update : 03/21 2014 (2062)

 

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