Effect of Sr substitution on electrical transport and thermoelectric properties of Y1−xSrxCoO3 (0≤x≤0.2) prepared by sol–gel process

The effect of Sr substitution on electrical transport and thermoelectric properties of Y1−xSrxCoO3 (0≤x≤0.2) has been investigated in the temperature range from 20 to 780 K. The Y1−xSrxCoO3 samples with different Sr concentrations have been synthesized by using the sol–gel process. The results show that dc electrical resistivity of Y1−xSrxCoO3 decreases remarkably with increasing Sr content x, which can be attributed to the reduction in lattice distortion. The Seebeck coefficients S of Y1−xSrxCoO3 are all positive, indicating predominant hole-type charge carriers, and they decrease monotonously with increasing Sr content of substitution. Moreover, experiments show that the power factor changes non-monotonously with Sr substitution with a maximum value of 2.69×10−5 W/m K2 at 650 K for the sample x=0.05, which is about five times greater than that for x=0, indicating that appropriate Sr substitution can effectively improve thermoelectric properties of Y1−xSrxCoO3.