High-temperature thermoelectric properties of Tix(ZrHf)0.99−xV0.01Ni0.9Pd0.1Sn0.99Sb0.01 half-Heusler alloys

Abstract The effect of Ti substitution at the Zr and Hf site on thermoelectric properties of Ti x (ZrHf) 0.99− x V 0.01 Ni 0.9 Pd 0.1 Sn 0.99 Sb 0.01 half-Heusler alloy compounds was investigated by finding the electrical resistivity, Hall effect, Seebeck coefficient, thermal conductivity and using X-ray diffraction. It was shown that substitution of Ti for Zr and Hf leads to a major reduction in the thermal conductivity and an enhancement of the Seebeck coefficient. The observed maximum Seebeck coefficient, minimum electrical resistivity, and minimum thermal conductivity at about 820 K are −206 μV K −1 , 0.71 mΩ cm, and 5.13 W m −1  K −1 , respectively. In addition, the dimensionless figure of merit is about 0.92 at about 820 K with a Ti content at x  = 0.3.