Magnetocaloric effect in HoMn2Si2 compound with multiple magnetic phase transitions

Abstract

The structural, magnetic and magnetocaloric properties of the polycrystalline compound HoMn2Si2 have been studied. The temperature variation of magnetization and heat capacity show that below room temperature the compound under goes multiple magnetic transitions, at about 80, 15 and 3.5 K respectively. Moreover, the presence of the interesting thermomagnetic irreversibility in HoMn2Si2 is detected in the magnetization versus temperature plot, which can be ascribed to the narrow domain wall pinning effect. A broad and asymmetric peak is observed for the MCE response which might suggest the underlying first-order nature of the transition and/or the spin fluctuations of the Mn subsystem. The density of states N(EF) at the Fermi level and the Debye temperature have been determined and analyzed. Large magnetocaloric effect (DSM ¼ 9 J/kg-K for a field change of 5 T around 9 K) suggest that this material is suitable for the low temperature magnetic refrigeration.