PhD (M/F): linking structure and properties in mono- and bi-metallic clusters and nanoparticles

Job Description

Thesis Subject

Correlating the atomic and chemical structure of metal clusters and nanoparticles to their electronic properties is central to the fundamental understanding of nanostructured materials. This PhD addresses this correlation in two closely related contexts:
1) Bimetallic nanoparticles are widely used in various applications such as catalysis and their physico-chemical properties strongly depend on the chemical configuration, i.e., on whether the metals alloy or segregate. In most cases it is unknown which chemical order is adopted in the ground state and how it changes upon exposure to reactive conditions (oxidizing, reducing).
2) For small clusters (smaller than 100 atoms), the role of the cluster surface and the detailed chemistry at its interface with a given environment has to be taken into account with atomic precision. The way how localized chemical bonds between a metal cluster and an oxide environment or reactive molecules impact its electronic structure is unclear and constitutes a real challenge for both experiment and theory.
The goal of this PhD project is to investigate these topics by combining optical spectroscopy with Transmission electron Microscopy (TEM) and derived spectroscopic techniques. These latter are used to derive quantitatively the spatial distribution of elements within individual nanoparticles. The clusters in question (Ag, Au, alloys such as AuPd or NiAg) all have surface plasmon resonances, which are used as a fingerprint of the particle's electronic structure. Notably the dependence of the plasmon resonance on environmental conditions gives important insight.

Your Work Environment

The aim of the NACRE project (financed within the PEPR DIADEM) is to investigate physically fabricated and surfactant-free bimetallic nanoparticles in controlled states (chemical ground state, under reactive conditions etc.) using different Transmission Electron Microscopy techniques. The experimental data are then treated using various machine learning techniques, both unsupervised and supervised, in order to extract the spatial distribution of chemical elements.
The GNOME project (financed by the ANR) aims at studying the influence of the environment on the plasmonic properties of small noble metal clusters.
The PhD candidate will fabricate metal clusters and nanoparticles using physical techniques. Metal cluster sources based on magnetron sputtering or laser vaporization, followed by gas aggregation and mass selection in the gas phase permit generating highly defined nanostructured samples. The nanoparticles are then investigated by TEM and by optical spectroscopy of the surface plasmon resonance, in-situ and under environmental conditions. The obtained results are compared to complementary experiments and theoretical simulations, all provided within the scientific projects and collaborations.
The candidate should hold a degree in physics or physical chemistry, prior experience in nanoscience, Transmission electron Microscopy or optical spectroscopy is an advantage.

The Institute for Light and Matter (Institut Lumière Matière - iLM) is a joint CNRS-University of Lyon 1 research unit located on the Lyon Tech La Doua campus.
With more than 300 employees, including a hundred doctoral students and post-docs, the iLM is a major player in physics and chemistry research in the Auvergne Rhône Alpes region, internationally recognized for the excellence of its research.
The continuum between fundamental research, responses to major societal challenges and innovation is at the heart of the unit's approach. The entire staff is committed to promoting excellence and ethical and responsible research.

Compensation and benefits

Compensation

2300 € gross monthly

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