Efficient Dopants for ZrNiSn Based Thermoelectric Materials

Four efficient n-type dopants have been found for ZrNISn based thermoelectric materials. These are Nb or Ta on the zirconium sites, and Sb or Bi on the tin sites. No suitable dopant was found for the nickel sites. In a (Zr sub (0.5) Hf sub (0.5) sub (0.99) Ta sub (0.01) NiSn alloy, a power factor of S sup 2 sigma = 22 muWK sup (-2) cm sup (-1) and a thermal conductivity of kappa = 5.4 x 10 sup (-2) WK sup (-1) cm sup (-1) were measured at 300K, resulting in a dimensionless figure of merit ZT = 0.12. These values are increased to S sup 2 sigma ~ 40 muWK sup (-2) cm sup (-1) and ZT ~ 0.5 at 700K.