Synthesis and Thermoelectric Properties of Pd-Doped ZrCoBi Half-Heusler Compounds

In this study, n-type Pd-doped ZrCo1-xPdxBi (x = 0, 0.03, 0.06, 0.09) half-Heusler samples were prepared by arc-melting and rapid hot-pressing sintering. The thermoelectric properties of ZrCo1-xPdxBi samples were analyzed and discussed. The results showed that the electrical properties of ZrCo1-xPdxBi, including electrical conductivity and the Seebeck coefficient, increase due to the substitution of Pd on Co site. The lattice thermal conductivity of ZrCo1-xPdxBi is markedly decreased because of the Pd/Co substitution. A minimum k(L) of 5.0 W/mK for ZrCo0.91Pd0.09Bi is achieved at 800 K. The figure of merit of ZrCo1-xPdxBi is boosted due to the depressed lattice thermal conductivity and the improved power factor. The highest value of figure of merit reaches 0.23 for ZrCo0.97Pd0.03Bi half-Heusler compound at 800 K.