STUDY OF PHONON HEAT TRANSFER IN METALLIC SOLIDS FROM MOLECULAR DYNAMICS SIMULATIONS

To describe the thermal behaviour of nanostructured materials and nanoelectronic devices, new properties and models have to be determined at the atomic scale. Recent experimental techniques such as near field microscopy1-2 allow to investigate heat transfer at small scales, but, the spatial resolution is still greater than 50 to 100 nm. This remains too large when the typical length of interest is a few nm. Moreover, at this scale, the sensor may have a significant influence on the temperature or the property to be measured. Numerical simulation is then the solution to study the matter at the atomic scale and to predict the thermophysical properties of solids. Molecular dynamics allows to simulate the material behaviour at the atomic scale3-4. It requires the knowledge of potentials that describe the interaction between atoms. As Si and Ge are semi conductors widely used for electronic components, accurate potential were determined for these materials5. Recently, heat transfer in nanostrutures made of Si or Ge has been studied and heat conductivity has been calculated6-7. Metallic solids are also widely studied using molecular dynamics. Due to their cristallographic structure, potentials8-9 are quite different than those used for semi conductors and leads to a more efficient implementation of the molecular dynamics. In metallic solids, the main contribution t