Effect of Cd isoelectronic substitution on thermoelectric properties of Zn0.995Na0.005Sb

The Cd isoelectrically substituted Na0.005Na0.995Sb samples were prepared by ball milling and hot press. The total thermal conductivity of Na0.005Na0.995Sb was decreased by Cd isoelectronic substitution caused by the mass and size fluctuation between Zn2+ and Cd2+. A high ZT value of 1.22 was obtained at 350 °C for Zn0.915Na0.005Cd0.08Sb sample, which was greater than that of other ZnSb based thermoelectric materials.