Enhancement of magnetocaloric properties by control of magnetocrystalline anisotropy in Ge doped MnFeHfPSi alloy

Abstract

This study investigated the improvement in magnetocaloric properties with magnetocrystalline anisotropy by Ge doping in MnFeHfPSi alloys. The maximum magnetic entropy change gets larger in alloys with higher magnetocrystalline anisotropy. This result is induced by the fractions of easy and hard magnetization planes. In addition, the magnetocaloric properties indicate large differences based on the direction between the easy magnetization plane and the applied magnetic field. Especially, the difference in magnetic entropy change under a low magnetic field is higher than that under a strong magnetic field. Besides, when magnetic transition occurs from a ferromagnetic to a paramagnetic state, the fraction of the easy magnetization plane decreases. Therefore, orientations with an easy magnetization plane play an important role in the enhancement of magnetocaloric properties.