Electronic, thermal and magneto-transport properties of the half-Heusler, DyPdBi

The electronic, thermal, and magneto-transport properties of the ternary half-Heusler, DyPdBi, crystallizing in a non-centrosymmetric face-centered cubic structure have been investigated. DyPdBi is known to exhibit anti-ferromagnetic (AFM) ordering and field-induced spin-flip transitions below the Neel temperature (T-N = 4.0 K). Our heat capacity measurements revealed a lambda-type anomaly near 4 K and a broad peak centering at similar to 50 K corresponding to the AFM transition and the Schottky effect, respectively. Both the electrical resistivity (rho) and thermal conductivity (kappa) data showed anomalies at the onset temperature of antiferromagnetic ordering suggesting the presence of spin-charge-phonon coupling. The temperature-dependent magnetoresistance (MR) behaviour revealed a sign crossover from negative to positive at 20 K while the maximum positive MR of 20% was obtained at T-N. The most interesting finding is the unusual field dependence of MR below T-N with an enhancement of positive MR following the field-induced magnetic transition attributable to the interphase boundary scatterings. Hall effect studies show holes are the dominant charge carriers with the density of signifying the semimetallic nature of DyPdBi. Below T-N, Hall resistivity is found to have additional contribution due to the anomalous Hall effect. The analyses of temperature-dependent Seebeck coefficient (S) and thermal conductivity behaviour suggest the presence of additional scattering mechanisms such as scattering between conduction electrons and narrow 4f derived Lorentzian shaped quasi-particle bands.