Thermoelectric and mechanical properties of ZrNi1+xSn Heusler composite alloy

Abstract

The thermoelectric and mechanical properties of in-situ developed half-Heusler and full Heusler composites in ZrNi1+xSn have been investigated. The structural analysis investigated by X-ray diffraction (XRD) reveals the materials a nanocomposite of half-Heusler (HH) as matrix phase and full-Heusler (FH) as inclusion. These nanocomposites exhibit low Seebeck coefficient and reasonably good electrical conductivity compared to the bare ZrNiSn half-Heusler. Interestingly, drastic reduction in thermal conductivity in these composites were noted which can be ascribed to distinct microstructures resulting to an effective phonon scattering from several grain boundaries and interface boundaries of HH and FH phase. Further, Hardness of these nanocomposites was measured using micro-hardness testing machine at an indentation load of 300g on different compositions.