Microstructural and compositional analyses of segmented YBa2Cu3O7-x NayCoO2 oxide thermoelectric ceramic prepared by hot-pressing method
Keywords:segmented oxide thermoelectrics, yttrium barium copper oxide, sodium cobalt oxide
YBa2Cu3O7-x-NayCoO2 (YBCO-NCO) oxide thermoelectric ceramic was successfully prepared by hot-pressing method. The optimum procedure included an applied weight of 1 ton, a temperature of 800 °C and 1 h holding time under an Ar atmosphere. The produced segmented bi-layer YBCO-NCO ceramic was highly dense with strong interfacial bonding and well-defined boundary. X-ray diffraction pattern of each layer showed the corresponding phase of each compound. At the interface, chemical bonding between two compounds was expected. This showed that, compared to the conventional sintering method, segmented layers of heterogeneous oxides could be effectively formed using the hot-pressing procedure.