Post-doctoral position on the DEIMOS beamlines : X-ray Magnetic Circular Dichroism under extreme experimental conditions

SOLEIL is the French national synchrotron facility, located on the Saclay Plateau near Paris. It is a multi-disciplinary instrument and research laboratory whose mission is to conduct research using synchrotron radiation, to develop cutting edge instrumentation on the beamlines, and to make these developments available to the scientific community. SOLEIL synchrotron, a unique tool for both academic research and industrial applications across a wide range of disciplines including physics, biology, chemistry etc., opened in 2008. It is used annually by thousands researchers from France and abroad. SOLEIL is based on a synchrotron source that is state-of-the-art both in terms of brilliance and stability. This large scale facility, a partner of the Université Paris Saclay, is a “publically owned” private company, founded by the CNRS and the CEA.

The DEIMOS beamline at Synchrotron SOLEIL is dedicated to X-ray absorption spectroscopy (XAS) with magnetic and natural circular and linear dichroism, notably XMCD, XMLD, XNCD and XNLD. It offers a unique combination of soft X-ray circular polarisation, a high-field (7 T) UHV cryomagnet, and an array of specialised sample environments designed to push the boundaries of spectroscopy under extreme conditions.

Over the past years, DEIMOS has developed several experimental platforms enabling studies at ultra-low temperatures (down to 200 mK using a dilution refrigerator), under in operando conditions (electric/magnetic stimuli), in liquid, and at high temperature (1000K). These developments are at the core of the beamline’s future scientific programme and form part of the broader upgrade strategy at SOLEIL.

The selected candidate will actively contribute to the commissioning, operation and scientific exploitation of these advanced sample environments. Particular emphasis will be placed on the dilution cryostat system (dichro50), the microfluidic flow cell and the V²TI insert designed for multiferroic and spintronic material studies under simultaneous magnetic and electric fields.

I.Missions

Under the supervision of the DEIMOS beamline scientists, the candidate will:

• Participate in the commissioning, optimisation, and scientific use of the ultra-low temperature dilution refrigerator and other extreme-condition sample environments (e.g. microfluidic flow cell, high-temperature setups, voltage/current-driven sample stages).
• Perform XAS and XMCD experiments on systems of current scientific interest (molecular magnets, correlated oxides, heterostructures, liquids...) in collaboration with internal and external users.
• Contribute to the technical development of new sample environments and detection schemes adapted to low-signal experiments.
• Support external users during beamtime and participate in internal beamline development experiments.
• Develop or adapt data analysis workflows and contribute to the improvement of the scientific throughput of DEIMOS.
• Disseminate results through presentations at international conferences and publications in peer-reviewed journals.

II.Qualifications and Expertises

Required:

• A PhD in Physics, Materials Science, Chemistry, or a related field.
• Solid background in magnetism, spectroscopy, or low-temperature physics.
• Hands-on experience with experimental instrumentation, preferably in a synchrotron or low-temperature/magnetic field laboratory.
• Strong data analysis skills; knowledge of Python or equivalent languages for data processing is a plus.
• Good communication and organisational skills.
• Fluency in English (spoken and written).

Desirable:

• Experience with X-ray absorption techniques (XMCD, XAS, etc.) or other synchrotron-based methods.
• Familiarity with UHV equipment, cryogenics, or multiphysics sample environments.
• Working knowledge of French is appreciated but not mandatory; language courses are offered.

III.General condition

The offer concerns a 1-year position. The extension of the post-doctoral position up to one year is a possibility.