Debye Temperature and Thermal Conductivity Variation in Non-Metallic Oxide of Aluminium at High Temperatures

Abstract

In the present article, the author studied the variation in the thermal conductivity of non–metallic oxides with respect to temperature. The thermal conductivity dependence on different parameters is considered in view of Leibfried-Schlomann relation. The change in lattice parameter is expressed in terms of volumetric change and is predicted using an equation of state (EoS). The expressions of Debye temperature and Grüneisen Parameter in terms of volumetric change are used. It is noted that Debye temperature decreases with increase in temperature in non-metallic oxides, however, the Grüneisen Parameter increases with temperature. Using Leibfried and Schlomann relation, the thermal conductivity is estimated in Non-metallic oxide. The model calculations depict the decrease in thermal conductivity with increase in temperature. The validity of the computed results is estimated by comparing them with Tang model results and the available experimental values. Thermal conductivity is determined for materials viz. MgO, Mg₂SiO₄, MgAl₂O₄, Al₂O₃. It is clear from the results that model explains well the thermal conductivity variation with temperature in non–metallic oxides.