Abstract 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 (ΔH) and at low temperatures together with a large normal reversible MCE under high ΔH 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 ΔH of 0–7 T, the values of −ΔSMmax (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.

中文翻译：

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RE 2 BaCuO 5 (RE = Dy 和 Er) 化合物中的大可逆正磁热和逆磁热效应

摘要 研究了多晶稀土铜酸盐Dy2BaCuO5 和Er2BaCuO5 中的磁热效应(MCE)。对于这两种化合物，在低磁场变化 (ΔH) 和低温下均观察到逆 MCE 以及在高 ΔH 下的大的正常可逆 MCE。这些行为对应于 Dy2BaCuO5 和 Er2BaCuO5 化合物中 AFM（反铁磁）基态和场诱导的变磁跃迁（一阶）从 AFM 到 FM（铁磁）态的事实。对于 0-7 T 的 ΔH，发现 -ΔSMmax（最大磁熵变）、RCP（相对冷却功率）和 RC（制冷剂容量）的值为 8.3 J/kg K、204 J/kg 和 153 J Dy2BaCuO5 为 /kg，Er2BaCuO5 分别为 9.6 J/kg K、230 J/kg 和 176 J/kg。