Effect of isovalent doping on the high temperature thermopower and resistivity properties of Ba2BiInO6

Ba2BiInO6 is a semiconductor which can be derived from Ba2Bi3+Bi5+O6 by substituting all the Bi3+ ions. Presently we report on the isovalent substitution of Sb5+ at Bi5+ site. Sb acts as a sintering aid as well as a dopant. Doping results in an increase in the resistivity as well as thermopower. All the doped compositions show degenerate semiconducting behavior at high temperature. The highest figure of merit obtained is 2.4×10−5 K−1 at 770 K for the x=0.06x=0.06 composition.