Effective thermal conductivity and diffusivity of GeSeSb glasses measured simultaneously as a function of temperature and fit to empirical equations

Abstract

Thermal transport properties like effective thermal conductivity (λe) and effective thermal diffusivity (ke) of Ge–Se–Sb chalcogenide glassy alloys were measured simultaneously using transient plane source (TPS) technique from room temperature to 260 °C at normal pressure. Twin pellets of the sample, prepared under a load of 5 ton, were used for these measurements. In the studied temperature range, both λe and ke initially remain almost constant from room temperature to 160 °C and then increase to maxima with further increase of temperature, and thereafter decrease with increasing temperature. This variation has been explained phenomenologically on the basis of variation of phonon mean free path with temperature. An effort has been made to predict this behavior by an empirical relation obtained from polynomial fit of the experimental data. The calculated values of λe and ke are in good agreement with the experimental results over the entire range of temperatures under investigation.