Reduced thermal conductivity in nanolamellar composite comprising half-Heusler and NiAs-type phases

The major drawback of half-Heusler-based thermoelectric materials lies in their relatively high thermal conductivity. In this work, nanolaminated structures composed of the half-Heusler phase MCoSb or M(Fe1−xNix)Sb and NiAs-type phase MSb (M = Ti, Zr) are fabricated by the arc-melting method. A significant reduction in the thermal conductivity is achieved due to effective phonon scattering in the nanolaminated structure, while the electrical resistivity is low enough for thermoelectric applications because of the formation of coherent interfaces.