Dramatic thermal conductivity reduction by nanostructures for large increase in thermoelectric figure-of-merit of FeSb2

Abstract

In this report, thermal conductivity reduction by more than three orders of magnitude over its single crystal counterpart for the strongly correlated system FeSb2 through a nanostructure approach was presented, leading to a significant increase of thermoelectric figure-of-merit (ZT). For the samples processed with the optimal parameters, the thermal conductivity reached 0.34 Wm−1 K−1 at 50 K, leading to a ZT peak of about 0.013, compared to 0.005 for single crystal FeSb2, an increase of about 160%. This work suggests that nanostructure method is effective and can be possibly extended to other strongly correlated low temperature thermoelectric materials, paving the way for future cryogenic temperature cooling applications.