Multi-functional properties of non-centrosymmetric ternary half-Heuslers, RPdSb (R = Er and Ho)

Abstract

We report here the observed unusual magnetoresistance, magnetocaloric effect and thermoelectric properties of half-Heuslers, ErPdSb, and HoPdSb, crystallizing in a non-centrosymmetric cubic structure. While ErPdSb exhibits a paramagnetic behaviour in the entire temperature range of our study (1.8-300 K), HoPdSb was found to order antiferromagnetically below 2.2 K. The magnetic entropy change was estimated to be ?48 and ?22 J (kg K)-1 at 2.5 K for Ho and Er sample, respectively, for a field change of 90 kOe, which is comparable or higher than the well-known magnetocaloric materials in this temperature range. The magnetoresistance (MR) behaviour was found to be a combination of positive and negative MR contributions analogous to that of the Weyl semimetals having non-trivial band structure (NbAs and TaAs) which can be modelled in terms of Adler-Bell-Jackiw anomaly. In addition, we observed low thermal conductivities for both these samples. Our studies clearly indicate that these half-Heuslers, HoPdSb and ErPdSb, exhibiting different properties can serve as multifunctional materials in various applications, specifically for ultra-low temperature applications. � 2018 IOP Publishing Ltd.