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

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. [ABSTRACT FROM AUTHOR]