High thermoelectric power factor in Fe-substituted Mo3 Sb 7

Abstract

Thermoelectric properties of the Mo2.57 Fe0.43 Sb7 compound, a ternary derivative of Mo3 Sb7, are reported from 2 up to 1000 K. Even though Fe substitution keeps low electrical resistivity values, high thermopower values are achieved at high temperatures. Electronic band structure calculations show that the high thermopower observed arises from the beneficial influence of iron d -states contribution to the density of states at the Fermi level. A high power factor similar to those of the best state-of-the-art thermoelectric materials emerges which, coupled with magnetic excitations that help to keep very low thermal conductivity values, leads to a dimensionless thermoelectric figure of merit of 0.55 at 1000 K. © 2010 American Institute of Physics.