Abstract
We have synthesized ZnO ceramics added with Ag or Y by the polymerized complex method. The microscopic structure and the thermoelectric properties such as Seebeck coefficient, electrical resistivity and thermal conductivity of the materials are much affected by the added elements. Ag metal or Y2O3 oxide was observed as a second phase in the sintered Ag-or Y-added samples, respectively. The crystal grain size of the Ag-or Y-added samples is much smaller than that of the non-added samples. The absolute values of the Seebeck coefficient and electrical resistivity for the Y-added samples increase with an increase of the Y content, while those for the Ag-added samples are almost constant independent of the Ag content. More reduction in the thermal conductivity was observed in the Y-added samples. These behaviors are ascribed to the physical properties of the precipitated second phases.