Lattice Thermal Conductivity and Correction Term of (GaN) compound

Abstract

The study surveys the ability of applying the dispersion relation of diatomic lattice provided by Awad, using the Nonequilibrium distribution function, to calculate the lattice thermal conductivity and correction term K for (GaN) compound at temperature range between (5-400K). The study approaches to a good agreement with the experimental values of the lattice thermal conductivity, especially in the maximum point of the conductivity curve. Also the present work shows very small values for the correction term and its percentage contribution, which could be neglected at wide range of temperature. We studied the effect of the Awad's temperature exponent m(T) on the lattice thermal conductivity and the correction term. The results showed the possibility of this function to deal with the high temperature lattice thermal conductivity of GaN. The paper studies the impact of the change in the relaxation rates of phonon scattering by the boundaries, point defects, three phonon and four phonon on the lattice thermal conductivity for both transverse and longitudinal phonons, where a significant impact on the conductivity curves, and difference in effectual values have been noted. The study appoints the temperature range of the activity of the phonon scattering