Realizing -type NbCoSn half-Heusler compounds with enhanced thermoelectric performance via Sc substitution.

-type half-Heusler NbCoSn is a promising thermoelectric material due to favourable electronic properties. It has attracted much attention for thermoelectric applications while the desired -type NbCoSn counterpart shows poor thermoelectric performance. In this work, -type NbCoSn has been obtained using Sc substitution at the Nb site, and their thermoelectric properties were investigated. Of all samples, NbScCoSn compound shows a maximum power factor of 0.54 mW/mK which is the highest among the previously reported values of -type NbCoSn. With the suppression of thermal conductivity, -type NbScCoSn compound shows the highest measured figure of merit  = 0.13 at 879 K.