Large reversible normal and inverse magneto-caloric effects in the RE2BaCuO5 (RE = Dy and Er) compounds

The magneto-caloric effect (MCE) in the polycrystalline rare-earth cuprates Dy2BaCuO5 and Er2BaCuO5 has been researched. An inverse MCE under low magnetic field changes (Delta H) and at low temperatures together with a large normal reversible MCE under high Delta H was observed for the both compounds. These behaviours are corresponding to the fact of AFM (antiferromagnetic) ground state and the field-induced metamagnetic transition (first order) from AFM to FM (ferromagnetic) state in Dy2BaCuO5 and Er2BaCuO5 compounds. For the Delta H of 0-7 T, the values of -Delta S-M(max) (maximum magnetic entropy change), RCP (relative cooling power) and RC (refrigerant capacity) are found to be 8.3 J/kg K, 204 J/kg and 153 J/kg for Dy2BaCuO5, and to be 9.6 J/kg K, 230 J/kg and 176 J/kg for Er2BaCuO5, respectively. (C) 2017 Elsevier B.V. All rights reserved.