Description du sujet de thèse

Scientific context
For fundamental thermal science dedicated to nanomaterials, there is currently no mature solution to the problem of thermal measurement at the nanoscale. This thesis is part of the ANTICHI (Advanced Nanoscale Thermal Imaging and CHaracterization Instruments) project, which aims to provide a versatile instrument that will allow the analysis of mesoscale thermal processes under highly controlled experimental conditions in order to understand the fundamental nature of heat transport and to measure the thermal conduction properties of materials at the nanoscale.

The ANTICHI project aims to develop and demonstrate a unique vacuum Scanning Thermal Microscopy (SThM) instrument capable of making contact thermal measurements under cryogenic conditions with both nanoscale spatial resolution and the ability to sensitively evaluate nanoscale heat transport over an extended temperature range (from 100 K to 300 K).
To achieve this, it includes (1) the development of a new SThM probe based on NbN resistive thermometry together with the necessary new instrumentation to improve its performance for cryogenic measurements, (2) a novel dual scanning thermal and electron microscopy (SThM-SEM) instrument equipped with a cooling stage to bring the sample to a temperature varying from 100 K to 300 K and to use the new NbN SThM probe.
In addition, since surface wear and contamination introduce large uncertainties in SThM measurements, the hybrid instrument will be optimised for in-situ cleaning of probes and samples. Adapted software and models will be developed for data processing and analysis. Finally, the instrument capabilities will be evaluated using protocols and reference samples previously developed for this purpose in collaboration with European national metrology institutes.
The demonstration of the instrument in the laboratory with reference samples for their low temperature behaviour will be the final achievement of the project.

Research project
The PhD student recruited by CETHIL will mainly perform tasks related to data processing and demonstration of the new dual scanning thermal and electron microscopy (SThM-SEM) engine at the different stages of its development, namely
- Development of an AFM equipped with a cooling stage to bring the sample to a temperature of between 100 K and 300 K, using commercial probes but also a new NbN SThM probe developed at the NEEL Institute in Grenoble,
- integration of the cryo-SThM into a SEM optimised by the Institute Lumière et Matière in Lyon for in-situ cleaning of the probe and sample before measurement, allowing correlative AFM, SThM and SEM analyses under very highly controlled conditions,
- Evaluation and demonstration by all partners of the capabilities of the final cryo-dual scanning thermal and electron microscopy measurement technique then developed on reference and high scientific impact samples selected for their low temperature behaviour.
Assisted by engineers and technical staff, the PhD student will therefore be involved in the various instrumental developments of the project for his/her own training; he/she will therefore be involved in all the WPs of the project.

Contexte de travail

The thesis will be carried out in the "Micro and Nanoscale Heat Transfer" (MiNT) team of the Centre for Energy and Thermal Sciences of Lyon (CETHIL), on the La Doua-LyonTech campus in Villeurbanne. The MiNT team, made up of around fifteen people including 5 permanent researchers and lecturers, is a pioneer in thermal AFM microscopy at European and world level.
The PhD work will be carried out in the framework of the ANR ANTICHI project, which brings together three French laboratories, long-standing partners, in Lyon and Grenoble: CETHIL and ILM (Lyon) and the NEEL Institute (Grenoble). The different scientific disciplines underpinning the ANTICHI project - physics (condensed matter), engineering (heat transfer, electronics) and metrology (resistive thermometry, SThM, cryogenics) - are all represented by recognised and leading research groups with a high degree of complementarity. Exchanges and stays in the partner laboratories are planned.

Informations complémentaires

Desired skills
You have a Master research project in experimental development and measurement. An experience in near field AFM and possibly (nano) thermal measurement and measurement would be a plus. Curious and open-minded, you are a person connected to the experimental bench, comfortable with experimental physics, you have knowledge of materials and electronic and you like disruptive nanotechnologies. Finally, you are comfortable in English, rigorous, motivated by taking risks.