A Modification of the Generalized Callaway Thermal Conductivity Equation to Allow for Phonon Dispersion

Abstract

The convenient approximation 3.: = o is often used in the formulation of the thermal conductivity integrals, which is in fact far from reality. In experimental dispersion curves of the magnitude and direction of the wave vector a. But for convenience of cal- culation and w do not obey a linear relation. w is generally a function a can be assumed a function of w . Joshi and Verma (1) suggested that a is a quadratic function of w . Later on it was modified by Sharma et al. (2) con- sidering that a is a cubic function of w , Thus according to Sharma et al.