M/F: post-doctoral position in surface science

Job Description

Missions

The PEPR COAST project brings together five laboratories (Institut Jean Lamour, IRCELYON, INSP, SOLEIL, and LORIA). It aims to develop intermetallics from the TM-sp families (where TM is a transition element and sp is a poor metal), potentially supported on oxides, as active and selective catalysts. From a sustainability perspective, these materials aim to reduce the use of critical elements in the context of the CO₂-to-methanol reduction reaction.

The project combines numerical, experimental, and methodological achievements. It aims to develop frugal "machine learning" approaches capable of making predictions and analyses that are precise enough to be usable with a minimum amount of data. To constrain the parameter space of the structural models necessary for interpretations, the idea is to integrate experimental surface science data (STM: scanning tunneling microscopy, XPS: photoemission, IRAS: infrared vibrational spectroscopy, GID: surface diffraction, LEED: low-energy electron diffraction). To this end, two oxidized systems under controlled conditions and exposed to probe molecules have been chosen: Pd-(Ga,Sn)-O and Pt-Sn-O, with the latter being the focus of the candidate's work at INSP.

On the three low-index orientations (111), (110), (100) of Pt, the idea is to form surface alloys by annealing from controlled Sn deposits under ultra-high vacuum and to study their oxidation as a function of temperature and pressure conditions to form epitaxial films. The targeted thicknesses range from sub-monolayer to a few atomic layers. The structure of the films will be addressed by LEED, and their surface will be imaged by STM up to atomic resolution. XPS will provide access to the chemical environment of the elements through core-level shifts. The idea is to establish a phase diagram as a function of the Pt substrate orientation, thickness, and oxidation conditions for these oxides at the nanometric scale. On the most representative epitaxial films, the adsorption configurations of probe molecules (CO, CO₂, CH₃COOH, H₂O) will be determined by surface IRAS. All results will be compared with atomistic simulations conducted by another postdoctoral researcher at INSP and by other collaborators of the COAST project. Depending on beamtime availability and the progress of the work, surface diffraction measurements at the SOLEIL synchrotron are possible.

Beyond the planned 12 months, the candidate will have the opportunity to continue for an additional year on similar surface science research topics, but within the framework of another ANR-funded project.

Activity

• Familiarization with the group's ultra-high vacuum surface science instrumentation (STM, LEED, STM, IRAS)
• Literature review and synthesis on the subject
• Determination of the formation conditions and structures of Pt-Sn surface alloys as a function of the crystalline orientation of Pt, the amount of Sn, and annealing conditions
• Growth of epitaxial SnOx/Pt films by high-temperature selective oxidation; determination of surface phase diagrams
• Surface analysis by STM (up to atomic resolution), XPS, and LEED
• Infrared vibrational spectroscopy (IRAS) measurements during molecule adsorption
• Possible participation in synchrotron surface diffraction experiments
• Data analysis, writing of syntheses, and presentations during internal meetings or within the COAST project
• Writing of articles and presentations at national/international conferences

Your Profil

Skills

The candidate must have:
• Solid knowledge in surface physics/chemistry.
• Proven experience in using ultra-high vacuum environments and associated techniques.
• Experience in scanning probe microscopy and/or photoemission spectroscopy (highly recommended).
• Autonomy in managing research work.
• Postdoctoral experience of less than 2 years (desired).

Your Work Environment

The Institut des NanoSciences de Paris (INSP) is a joint research unit (UMR 7588) of the CNRS and Sorbonne Université. Its 200 members are divided into 9 teams whose work is at the heart of current issues in nanoscience. They develop fundamental research around the study of new properties that emerge whenever physical phenomena are confined in nano-objects.

The candidate will be welcomed within the "Oxides in Low Dimensions" team (15 members; link). This team brings together experimentalists and theoreticians interested in dimensionality reduction effects in oxide materials. Through joint experimental/theoretical work, it has developed a recognized expertise in oxide surface science (surfaces, thin films, nano-objects). Its activity relies on long-term collaborations with other academic teams, both national and international, as well as with the research centers of major industrial groups (Saint-Gobain and ArcelorMittal). It develops a limited number of long-lasting scientific themes: atomic and electronic structure, nature of defects, polarity, reactivity, adhesion, hydroxylation, dissolution/precipitation, metal/oxide contact. These are mainly studied on binary oxides in various forms (crystals, thin films, nanopowders), in environments ranging from ultra-high vacuum to liquid media or in contact with metals.

Under the direction of R. Lazzari (CNRS Research Director), the candidate will interact with all members of the group, not only experimentalists but also theoreticians. He/she will benefit from the technical support of two engineers and will be specifically responsible for one vacuum instrumentation (STM/XPS/LEED) while having access to all available tools (e.g., IRAS).

Constraints and risks

None

Compensation and benefits

Compensation

Between 2 991,58 € adn 4 756,76 €

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions