THERMOELECTRIC-POWER OF SUPERCONDUCTING BA-K-BI-O CRYSTALS

We have measured the thermopower and resistivity of Ba1-xKxBiO crystal s with superconducting transition temperatures T-c close to 30 K. The thermopower is very small, decreasing above T-c as temperature increas es up to about 150 K; at higher temperatures, a flattening of the temp erature dependence or an increase is observed. These features are comp ared to those seen in the cuprate high-temperature superconductors. Th e resistivity increases approximately linearly with temperature, but t he slope lessens somewhat below about 100 K.