Magnetic properties and magnetocaloric effect in metamagnetic RE2Cu2O5 (REÂ =Â Dy and Ho) cuprates

The magnetic and magnetocaloric properties in Dy2Cu2O5 and Ho2Cu2O5 cuprates have been investigated. The RE2Cu2O5 compounds show a typical paramagnetic (PM) to antiferromagnetic (AFM) transition under low field around 10.3 and 13.5 K for RE = Dy and Ho, respectively. And a field-induced metamagnetic transition from AFM to ferromagnetic (FM) phase was happened with the application of higher magnetic field for both compounds. An inverse MCE under low magnetic field change and at low temperatures together with a normal reversible MCE under high magnetic field change was observed for the present RE2Cu2O5 compounds, which is related to the fact of the AFM state and the field-induced first order metamagnetic transition from AFM to FM state, respectively. The maximum values of magnetic entropy change (−ΔSMmax) are 12.0 and 12.4 J/kg K under a field change of 0-7 T for Dy2Cu2O5 and Ho2Cu2O5, with the values of the relative cooling power (RCP) of 273 and 256 J/kg, respectively.