Investigation on the magnetocaloric effect in RNi2 (R: Dy, tb) melt-spun ribbon

• We investigate the effects of texture on the MCE of a melt-spun ribbon and a composite formed by RNi2 (R=Dy and Tb).
• We compare the experimental data of MCE of a bulk and melt-spun ribbon.
• We have successfully modeled the MCE in bulk and melt-spun ribbon considering the magnetic field applied along the easy magnetic axis and also averaged over all of the possible directions.
• We describe a possible source of the increase in potential magnetocaloric.

We report a theoretical and experimental investigation on the magnetocaloric properties of the rare earth RNi2 (R=Dy,Tb) in melt-spun ribbon and bulk form. The theoretical calculations were performed using a Hamiltonian model including the Zeeman-exchange interactions and the crystalline electrical field. Thus the magnetocaloric potential was calculated in the easy magnetic axes, in order an average over all of the possible directions. The isothermal entropy-change dependence on temperature calculated was compared with available experimental data for melt-spun ribbon and bulk material. We also investigated, theoretically and experimentally, the behavior of a DyNi2 and TbNi2 composite with optimized molar proportions and discussed this in the context of the optimum regeneration Ericsson cycle.