Efficient dopants for ZrNiSn-based thermoelectric materials

Four efficient n-type dopants have been found for ZrNiSn-based thermoelectr ic materials. These are Nb or Ta at the zirconium sites, and Sb or Bi at th e tin sites. No suitable dopant was found for the nickel sites. In a (Zr0.5 Hf0.5)(0.99)Ta0.01NiSn alloy, a power factor of S(2)sigma = 22 mu W K-2 cm( -1) and a thermal conductivity of kappa = 5.4 x 10(-2) W K-1 cm(-1) were me asured at 300 K, resulting in a dimensionless figure of merit ZT = 0.12. Th ese values are increased to S(2)sigma approximate to 40 mu W K-2 cm(-1) and ZT approximate to 0.5 at 700 K.