Thermoelectric properties of A0.05Mo3Sb5.4Te1.6 (A = Mn, Fe, Co, Ni)

Mo3Sb7−xTex was earlier reported to be a promising p-type thermoelectric material for high temperature applications, with Ni0.06Mo3Sb5.4Te1.6 achieving a ZT of 0.93 at 1023 K. In order to investigate the effect of using different transition metal atoms and to further improve the thermoelectric properties, a variety of transition metal atoms (Mn, Fe, Co and Ni) were intercalated into the voids of empty Sb atom cubes. Our results indicate that Fe0.05Mo3Sb5.4Te1.6 and Ni0.05Mo3Sb5.4Te1.6 exhibit a higher power factor than Mo3Sb5.4Te1.6. Fe0.05Mo3Sb5.4Te1.6 demonstrates the highest ZT value at 673 K (ZT = 0.31), significantly higher than Mo3Sb5.4Te1.6. Thermal analysis proves Ni0.05Mo3Sb5.4Te1.6 to be phase stable at least until 1250 K in an inert atmosphere, an important prerequisite for high temperature applications.