Enhanced thermoelectric properties of iron doped compound (Zn1 − xFex)4Sb3

The thermoelectric properties of Fe-doped compounds (Zn1 − xFex)4Sb3 (x = 0, 0.0025, 0.005, 0.01) have been studied at the temperatures from 7 K to 305 K. The results indicate that low-temperature (T < 300 K) thermal conductivity of the moderately doped (Zn1 − xFex)4Sb3 (x = 0.0025 and 0.005) reduces remarkably as compared with that of Zn4Sb3 due to enhanced impurity (dopant) scattering of phonons. Electrical resistivity and Seebeck coefficient are found to increase first and then decrease obviously with the increase in the Fe content. Moreover, the lightly doped compound (Zn0.995Fe0.005)4Sb3 exhibits the best thermoelectric performance due to the improvement in both its thermal conductivity and Seebeck coefficient, whose figure of merit (at 300 K), ZT, is about 1.3 times larger than that of β-Zn4Sb3 obtained in the present study.