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Reference : UMR6634-CHRVUR-030
Workplace : ST ETIENNE DU ROUVRAY CEDE
Date of publication : Friday, June 4, 2021
Scientific Responsible name : Jean Juraszek
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
This PhD subject concerns the study of magnetic properties of chalcogenide thermoelectric materials, in the framework of the search for new materials for energy hardvesting, and more specifically for the recovery and conversion of thermal energy into electricity. The aim is to investigate compounds with a spinel structure, whose electronic and magnetic properties can be very varied depending on their chemical composition. It has recently been shown that the application of a magnetic field can influence the thermoelectric properties (including the Seebeck coefficient) in oxides and sulphides, but the coupling mechanisms between transport and magnetism are still poorly understood.
The objectives of the thesis are to provide a better understanding of this coupling in iron-based spinels through the determination of the magnetic order at the local scale by 57Fe Mössbauer spectrometry. The latter technique, by locally probing hyperfine interactions at the 57Fe nucleus, provides unique insight into its chemical, electrical and magnetic environment. It will then be possible to determine the valence state of iron, its magnetism and the charge transfer mechanism, in order to analyze the thermoelectric properties, and better understand the different terms contributing to the Seebeck coefficient.
The doctoral student will be in charge of conducting the magnetic and Mössbauer spectrometry measurements at different temperatures and different applied magnetic fields, as well as the analysis of the data (adjustment of the spectra) and their interpretation, in connection with structural and physical properties, partly characterized in close collaboration with the CRISMAT laboratory in Caen, within the framework of the SPINTEP project of LABEX EMC3/RIN.
The research laboratory "Group of Physics of Materials (GPM)" is a Joint Research Unit (UMR 6634) associated to University of Rouen Normandie, INSA of Rouen Normandie (both members of the federation of Normandy University) and affiliated to the French National Research Center (CNRS) as a member of the Institute of Physics (INP) and also of the Institute of Engineering and Systems Sciences (INSIS). The laboratory has developed a strong expertise in scientific instrumentation and in material characterization down to the atomic scale, with a special emphasis on the connection between nanoscaled structures and properties. It is organized in five Scientific Departments : Scientific instrumentation, Metallurgy Microstructures and Mechanics, Functional Materials and Nanostructures, Disordered Systems and Polymers, Thematic Openings and Innovations. The laboratory is located in the premises of the University of Rouen Normandie and the INSA of Rouen Normandie, on the science campus of the “Technopôle du Madrillet” (situated in the south of Rouen city). The laboratory has 160 staff (60 professors, assistant professors and full time scientists; 30 application engineers, technicians and administrators; about 70 PhD students, post-docs and guest researchers).
The candidate will be affected to the “Functional Matrials and Nanostructures” department in the “Functional Materials and Magnetism” team. This research team is working on fundamental studies of various kind of magnetic materials/nanomaterials (alloys, oxides, sulfides,...) in bulk or thin film shape, for low environmental impact and/or energy consumption applications.
Constraints and risks
Work under ionising radiation (gamma radiation related to Mössbauer spectrometry measurements) in restricted area. A radiation safety training will be delivered at the beginning of the position.
Desired profile or skills :
Master degree in Physics/Material Science. The candidate must have a high aptitude for experimental work, but also a thorough knowledge in Solid State Physics.
subject to obtaining EMC3 LABEX/RIN funding for the project
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