Thermoelectric properties of WO3-based ceramics doped with Co2O3

Tungsten trioxide (WO3) doped with cobalt sesquioxide (Co2O3) was prepared by a conventional mixed oxide processing route and the thermoelectric properties were studied from 300 up to 1,000 K. The addition of Co2O3 to WO3 resulted in an increase in both the grain size and porosity, indicating that Co2O3 promotes the grain grown of WO3. The magnitude of the electrical conductivity (sigma) and the absolute value of the Seebeck coefficient (|S|) depended strongly on the Co2O3 content. As for the power factor (sigma S (2) ), the 5.0 mol% sample has the maximum value of the power factor which is 0.12 mu Wm(-1)K(-2) at 873 K.