Oriented mosaic model analysis of anisotropic thermoelectric properties of heterogeneous materials

Abstract

Thermoelectric properties of heterogeneous materials are discussed in terms of a randomly oriented rectangular plate-like mosaic of anisotropic crystalline grains embedded in a homogeneous host material. Anisotropies in effective thermoelectric parameters and the values of thermoelectric parameters can be related to the mean orientation of the plate-like grains which, in turn, can be related to the orientation factor of Lotgering. They are also functions of various parameters such as dimension ratios α, α′ and α″ of electrical resistivities, thermal conductivities, and the Seebeck coefficient, respectively, of grains to those of host medium. Use of f-dependent anisotropies in conjunction with relative magnitudes of electrical and thermal conductivities as well as of the Seebeck coefficient, allows α, α′ and α″ to be estimated, which characterize the intergranular medium.