(AgBiTe₂)_1-x(Ag₂Te)_x複合材料の熱電特性

抄録

Thermoelectric figure of merit of AgBiTe₂ -Ag₂Te composites is increased by scattering efficiently long-wavelength phonons^{1, 2} at the boundaries between AgBiTe₂ and Ag₂Te. We prepared AgBiTe₂ alloys dispersed with Ag₂Te grains of (AgBiTe₂)_1-x(Ag₂Te)_x(0<x<1). Electrical conductivity, Seebeck coefficient, and thermal conductivity of AgBiTe₂-Ag₂Te composites depended on contents, sizes and textures of Ag₂Te grains. Comparing the experimental values with the calculated values based on conductivity equation^{3, 4, 5, 6} with no phonon and electron scattering at the boundaries, we have found that the thermoelectric figure of merit has the maximum when the Ag₂Te grain size is around 10μm, when the phonon scattering is larger than electron scattering.