Magnetocaloric and magnetotransport properties in RRhSn (R = Tb-Tm) series

We have synthesized polycrystalline RRhSn (R=Tb-Tm) compounds, which crystallize in the hexagonal structure with space group P (6) over bar 2m. All the compounds, except HoRhSn, are antiferromagnetic at low temperatures. TbRhSn and DyRhSn show multiple magnetic transitions and metamagnetic behavior. Heat capacity and electrical resistivity data in different temperature regimes were fitted to identify various contributions to them. Magnetocaloric effect (MCE) in all the compounds has been calculated in terms of the isothermal magnetic entropy change and the adiabatic temperature change. ErRhSn and TmRhSn show Schottky anomaly in the heat capacity data. Among the compounds studied, HoRhSn shows the maximum adiabatic temperature change of 6.5K for a field of 50 kOe. DyRhSn and TmRhSn also show large positive magnetocaloric effect below 10 K. A sign reversal accompanied by a large positive magnetoresistance (MR) at low temperatures appears to be a common feature in this series of compounds. Narrow domain wall dynamics appears to be the main reason behind the large positive magnetoresistance in all the compounds. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4766900]