Job description:
SOLEIL is the French national synchrotron facility, located on the Saclay Plateau near Paris. It is a multi-disciplinary instrument and a research laboratory, whose mission is to run research programs using synchrotron radiation, to develop state-of-the-art instrumentation on the beamlines, and to make those available to the scientific community. SOLEIL, a unique tool for both academic research and industrial applications across a wide range of disciplines including physics, biology, chemistry etc., is used by over 5 000 researchers coming from France and abroad. The facility is a “public” company employing about 500 people, founded by the CNRS and the CEA, and partner of the Paris-Saclay University.
Applications are invited for one PhD position at Synchrotron SOLEIL that enters into a EU-funded Marie Skłodowska-Curie Innovative Training Network (ITN), “PANORAMA (EuroPean trAining NetwOrk on Rare eArth elements environMental trAnsfer: from rock to human)”, in which are involved 9 member institutions, from both academia and industry, located in France, Germany, Portugal, Belgium, Italy, Spain and United Kingdom, together with 5 partner organisations. A total of 15 PhD students will be hosted across the network. They will take part in laboratory-based research, filed investigations, as well as a networkwide training program through workshops and summer schools. Additionally, collaboration with network partners will occur through short-term placements in industrial/academic partner laboratories in Portugal and France (Rennes).
Detailed mission:
I.Description of the project:
Rare earth elements (REE) are crucial to a wide range of modern technologies (e.g. catalytic additives, hybrid vehicles, wind turbines, oil refining and lighting technologies) relying on their chemical, optical and electro-optic, and paramagnetic properties. They are thus more and more intensively used and are now considered as ‘emerging’ pollutants. However, the environmental risk exerted by REE has yet received little attention because of their quite recent applications and many uncertainties remain in our understanding of the REE anthropogenic sources and transfer. In that context, the overall PANORAMA’s research objective is to elucidate the man-induced environmental dissemination of REE and the associated effects on the environmental health.
The proposed thesis project aims at contributing to the understanding and prediction of REE behavior in soil systems. In this topic, it will combine field investigations on an ancient mining site with sample synthesis and characterization to feed into predictive modelling of REE transfers. The work will focus on the characterization of REE interactions with mineral oxide surfaces through two representative REE Neodymium (Nd) and Samarium (Sm) as they enter into permanent magnet composition (NdFeB and SmCo), which demand is increasing for green energy technology; Sm being a REE with two oxidation states. Relevant mineral surfaces of Fe/Al oxides will be selected as model, according to the mineral composition of the old mine field studied. REE – surface interactions (including adsorption and coprecipitation) under various physico-chemical conditions (pH, redox, T, concentration, etc.) and sorbing phases ageing will be characterized using Surface-XAS and Resonant XPS. Emphasis on advanced X-ray absorption and diffraction techniques such as HERFD-XANES and Bragg-CDI will be made for this application. The results will be applied to field systems and serve as inputs in transport models.
II.Method
- (1) Field investigations on an ancient mining site
- (2) Synthesis of representative REE – mineral oxides interactions systems (i.e Nd and Sm on Fe/Al oxides, as a function of various physico-chemical conditions of formation)
- (3) Characterization of oxides structures and REE-surfaces interactions
- (4) Surface interactions modelling
- (5) Implementation of predictive models for REE behavior in environmental systems
III.Expected results
New decisive data regarding adsorption phenomena of REE on oxide minerals, as a function of physico-chemical conditions. Implementation of predictive REE transport models.
Profile:
IV.Profile and skills required
- Master in geosciences or equivalent ;
- Experience in field geology ;
- Skills in geochemistry ;
- Strong motivation to learn and participate to laboratory work, including synthesis, mineral characterization and measurements by a variety of techniques (X-ray diffraction, scattering, X-ray absorption spectroscopy, …) ;
- Good ability to communicate in English (spoken/written) or in French.
V.General conditions and hiring procedure
Candidates will be required to meet the Marie Skłodowska-Curie Early Stage Researcher eligibility criteria. In particular, at the time of appointment, candidates must have had less than four years full-time equivalent research experience and must not have already obtained a PhD. They must not have resided in France for more than 12 months during the 3 years immediately before the appointment.
This full-time post will be available from October 2020 and is offered on a fixed-term 36 month contract.
Informal enquiries may be addressed to the supervisor : Dr. Delphine VANTELON – Tel: +33 (0)1 69 35 96 94 – [email protected].
The successful candidate will be register for a PhD at Paris Saclay University in the SMEMAG (Sciences Mécaniques et Energétiques, Matériaux, Géosciences) doctoral school.