Magnetic and magnetocaloric properties of Dy5Pd2: role of magnetic irreversibility

Abstract

In this report the magnetic behavior and magnetocaloric response of the intermetallic compound Dy₅Pd₂ has been investigated from detailed magnetization measurements. Magnetic cluster glass behavior has been observed in the crystalline Dy₅Pd₂ compound below 38 K. Magnetocaloric entropy changes evaluated using Maxwell’s relation (MXR) from zero-field-cooled magnetization isotherms, which is used mostly in the literature, shows a giant inverse magnetocaloric effect (MCE) below 20 K and a large conventional MCE around 60 K in this compound. The observed value of inverse MCE is ∼29 J kg⁻¹ K⁻¹ for 50 kOe external magnetic field change at T = 3.5 K. In this context, the origin of the giant inverse MCE and its temperature dependence has been studied. The applicability of MXR and procedure to obtain reversible MCE using MXR which is important for practical application has been discussed. Dy₅Pd₂ exhibits a reversible MCE with a peak value of magnetic entropy change (ΔS^max_M) 8.3 J kg⁻¹ K⁻¹ at 60 K under a magnetic field of 50 kOe and an irreversible inverse MCE below 20 K.