The thermoelectric properties of mixed oxides ln2O3-MOx(MOx=Cr2O3, Mn2O3, NiO, ZnO, Y2O3, Nb2O5, SnO2) are investigated in terms of the thermoelectric materials at high temperature. The Seebeck coefficients, S, of all the samples have negative values, and those of ln2O3•SnO2 and ln2O3•ZnO increase linearly with temperature, attaining values of -90 and -210 μV K-1 at 1000 °C, respectively. The electrical conductivities, σ, of these oxides are significantly high. The power factor S2σ of the oxides has constantly positive temperature coefficients up to over 1000 °C. Rather low thermal conductivities, k, of the sintered bodies of the oxides, ca. 1.7 W m-1 K-1 at room temperature, lead to the largest value of the thermoelectric figure of merit Z=0.4 × 10-4 K-1 for M = Sn at 1000 °C, and the Z value increases toward higher temperatures.
All Science Journal Classification (ASJC) codes
- Materials Chemistry