PhD Position (M/F): Thermal Transport in Magnetic Particulate Materials: From the Nanoscale to the Macroscale

Job Description

Thesis Subject

Key Scientific Challenges and Objectives
- Multi-scale inconsistency
At present, no robust analytical or numerical framework links the microscopic parameters of particles (anisotropy, volume, interactions) to macroscopic thermal conductivity without losing information about local temperature gradients. The project will generalize our Green's function model from 1D chains to full 3D nanoparticle assemblies, providing an analytical temperature field T(r,t) driven by the dissipated power Pi(T) of each particle.
- Long-range magnetic interactions
In metallic and semiconductor matrices, long-range dipolar interactions and oscillatory RKKY exchange interactions profoundly modify the collective magnetic state, the specific absorption rate (SAR), and therefore the heat sources themselves—a feedback mechanism that is not captured by standard thermal models.
- Kapitza interfacial resistance
Spin–lattice energy transfer at the nanoparticle (NP)/matrix interface is limited by phonon impedance mismatch. The project will seek to develop microscopic models of interfacial phonons, replacing phenomenological fitting parameters with physically grounded conductance values.

Doctoral Research Plan (36 Months)
Year 1
Literature review.
Familiarization with spin dynamics (LLG) codes.
Extension of the Green's-function thermal model to 3D assemblies.
Implementation of anisotropic RKKY interactions in the stochastic LLG code.
First visit to ILM to understand synthesis and measurement constraints.
Year 2
Parameterization of the multiscale model using real structural and magnetic inputs.
First quantitative comparison between predicted and experimentally measured thermal conductivity κ(H,T) using thermoreflectance techniques.
Year 3
Systematic numerical exploration of the parameter space.
Development of “thermal phase diagrams” mapping the signature of the blocking transition in thermal transport.
Writing of the dissertation manuscript and publication of research results.
Desired Candidate Profile

We are seeking a candidate with:
A strong background in theoretical condensed matter physics (Master's degree or equivalent).
Strong analytical skills and demonstrated experience in computational modeling (Python and/or C++).
Familiarity with statistical physics and/or magnetism.
A genuine interest in multiscale approaches and in the interaction between theory and experiment.

Your Work Environment

The PhD research will be conducted at the PROMES laboratory under the supervision of a team of leading experts in the field. Regular exchanges and visits between Perpignan and ILM (Lyon) will be organized to ensure close integration between theoretical developments and experimental investigations.

Constraints and risks

No specific risks are associated with the theoretical research activities conducted as part of this doctoral project.

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

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