Understanding thermoelectric properties in NbCoM0.05Sn (M = Fe, Co, Ni, Cu) half-Heusler compounds by temperature-dependent diffraction

Intrinsic interstitial defects are thermodynamically favorable in high-temperature synthesized half-Heusler compounds and manipulate the thermoelectric properties (improving electrical conductivity & reducing lattice thermal conductivity). They provide a new pathway to boost thermoelectric performance. Here, NbCoSn & NbCoM0.05Sn (M = Fe, Co, Ni, Cu) were synthesized to study the effect of different excessive metals on crystal structure, thermoelectric properties, and to probe correlation between them. To bridge the correlation between interstitial defects and electrical properties of NbCoM0.05Sn, the temperature dependence of interstitial defect site occupation factors in conjunction with transport properties need to be investigated.