Preparation and thermoelectric properties of pseudogap intermetallic (Ti1-xVx)NiSi solid solutions

We theoretically and experimentally investigated the thermoelectric (TE) properties of TiNiSi-based solid solutions with a pseudogap at the Fermi level in the electronic band structure. Calculation of the TE properties of TiNiSi predicted that electron doping of TiNiSi leads to a higher power factor than hole doping. According to this prediction, we prepared the partially V-substituted TiNiSi-based compounds (Ti1-xVx)NiSi (x = 0, 0.05, 0.10, 0.15, and 0.20) using arc-melting and subsequent spark plasma sintering. An increase in the V content x improved the n-type TE properties: the absolute values of the Seebeck coefficient and electrical conductivity both increased, while the thermal conductivity slightly decreased. The highest dimensionless figure-of-merit, zT, was 0.032 at 600 K, obtained for the x = 0.20 sample.