Preparation and thermoelectric properties of ZnO-TiB/sub 2/ composites

ZnO and TiB/sub 2/ are chosen as a thermoelectric (TE) phase and a highly conducting phase, respectively, to construct two-phase ball-shell-type composites. ZnO-coated TiB/sub 2/ powders are prepared via sol-gel processing and are then hot pressed in vacuum. The TiB/sub 2/ grains in the hot-pressed composite samples are coated with an interfacial layer that consists of Zn/sub 3/B/sub 2/O/sub 6/, TiO/sub 2/, Zn/sub 2/TiO/sub 4/, and ZnB/sub 2/O/sub 4/, rather than ZnO, due to the reactions between ZnO and TiB/sub 2/ during sintering. The thermal and electrical conductivity and Seebeck coefficient of the composites were measured in dependence on temperature. The thermoelectric properties of the composite samples are compared to pure ZnO.