Abstract:
‘In this talk, first I will give a review of the experimental and theoretical methods for the measurement of thermal conductivity of solids. Thermal conductivity has been studied over two hundred years, but many of its details in small sizes and atomic scale are still unknown. Heat carriers such as phonons, electrons, magnons and photons and their interactions between them play a wide role in many physical phenomena at the atomic scales. So, our knowledge of these phenomena and their effects on other properties of materials enables us to understand the properties of materials and designing efficient materials. In many simple crystalline systems phonon–phonon interactions play a primary role in thermal conductivity. So I will focus on the category of phonon dominated methods such as lattice dynamics calculation and molecular dynamics simulation. In the second part of the talk, I will describe our formalism and results for calculating Thermal conductivity of strongly anharmonic materials at ultra high-temperatures. In this case we used an effective harmonic theory obtained from sampling of the phase space in the canonical ensemble.’ (c)