Microstructure and thermoelectric properties of ZnO and (Zn0.98Al0.02)O thermoelectric material sintered from ultra fine oxide powder

Thermoelectric properties of ZnO and (Zn0.98Al0.02)O alloys sintered under different pressures, from ultra fine powder have been investigated. The samples are with a grain size under 10 mu m. Electrical conductivity, Seebeck coefficient and thermal conductivity of the samples are measured at temperatures ranging from 337 to 973 K. Electrical conductivity of the samples decreases with increasing temperature. Seebeck coefficient of the samples showed negative and the absolute value increased with increasing temperature. Thermal conductivity of the samples decreased with increasing temperature. The electrical conductivity and Seebeck coefficient appeared relatively insensitive to grain size, while the thermal conductivity did.