Microwave sintering of Ge-doped In2O3 thermoelectric ceramics prepared by slip casting process

Abstract : Ge doped In2O3 bulks were prepared by dry uniaxial compaction or slip casting shaping methods followed by a conventional or microwave sintering. Density of slip casted Ge doped In2O3 samples after conventional sintering reaches bulk density close to the theoretical one thanks to an optimized particles arrangement in the slip casted green bulks. Combined with a fast microwave sintering, slip casted bulks possess submicrometer grain size due to limited grain growth. A significant decrease of the electrical resistivity has been measured in slip casted samples sintered by conventional heat treatment. In bulk specimens sintered by microwave heating, a simultaneous increase of electrical resistivity and decrease of the thermal conductivity is observed. From room temperature to 1000K in air, slip casted samples sintered by conventional or microwave sintering exhibit similar thermoelectric figure of merit (ZT) values. © 2014 Elsevier Ltd.