Improvement of thermoelectric properties by dispersing Ag2Te grains in AgBiTe2 matrix:: Composition effects in (AgBiTe2)1-x(Ag2Te)x

We prepare composite materials that Ag2Te grains were dispersed in AgBiTe2 matrices with the compositions of (AgBiTe2)(1-x). (Ag2Te)(x). The textures depend on the composition. We measured electrical conductivity, thermal conductivity, Seebech coefficients and Hall coefficients as a function of the composition. Based on these data, we estimate Hall mobility and lattice thermal conductivity, and finally thermoelectric figure of merit. We show that the figure of merit is enhanced in the composite system by means of enhancement of phonon scattering at the grain boundaries.