Thermal conductivity control of ZnO thermoelectric ceramics using hot-pressing method

Nanostructural ZnO ceramics was prepared using Al doped ZnO nano-powders by low-temperature HPing at 950/spl deg/C for 3h. Al-doped ZnO nano-powders was obtained by chemical processing of both co-precipitation and spray drying at 120/spl deg/C. Power factor of the prepared ZnO ceramics is 5.0/spl times/10/sup -4/ Wm/sup -1/K/sup -2/, which increased ca. 20% by HP sintering at 950/spl deg/C. The prepared nanostructural ZnO ceramics showed lower thermal conductivity than that of normal sintered ceramics at the lower temperature range.