Multi-band simultaneous fits of transport data on p-type ScNiSb with including impurity conduction

Abstract

The experimental data of the electrical conductivity [Formula: see text] and the Seebeck coefficient [Formula: see text] in the temperature range from 2 K to 950 K, together with those of the Hall coefficient [Formula: see text] in the temperature range from 2 K to 300 K, on the polycrystalline sample of [Formula: see text]-type ScNiSb reported by Ciesielski et al. [Phys. Rev. Appl. 14, 054046 (2020)] have been critically analyzed with including both nearest-neighbor and Mott variable-range hopping (VRH) conduction. Through the simultaneous fits to the experimental data of [Formula: see text], [Formula: see text] and [Formula: see text], various transport parameters such as the bandgap energy, the effective masses of holes and electrons, and the electron-to-hole mobility ratio, are deduced together with the ionization energy and the concentration of the acceptor level. It is shown that nearest-neighbor hopping (NNH) conduction exhibits a significant effect on the Seebeck coefficient at low temperatures while VRH conduction has an only small effect on it. Contrary to the speculation by Ciesielski et al., the electron mobility is proved to be lower than the hole mobility.