Abstract In a lower magnetic field, perovskite manganese oxide has the prodigious potential of room temperature magnetic refrigeration because of its simple preparation, low cost and stable structure. In this paper, a series of polycrystalline nanomaterials La0.8-xSr0.2SmxMnO3(x = 0,0.05,0.1,0.15,0.2) were prepared by sol–gel method. The XRD patterns showed that the crystal structure of samples was rhombohedral and the surface morphology seen by SEM was ellipsoidal. The variation of magnetization with temperature and external magnetic field was measured by a superconducting quantum interferometer. By deducing and calculating, the ideal magnetic parameters are the maximum magnetic entropy change, Curie temperature and relative cooling power. Finally, It was found that when the doping amount of Sm3+ was in the range of 0.1 to 0.15, the Curie temperature was controlled in the range of 266 K to 303 K. Under the applied magnetic field of 5 T, the maximum magnetic entropy change was up to 4.03Jkg-1K−1, and the maximum relative cooling power applicable to room temperature reached 295.31 J/kg, equivalent to 72.03% of the metal gadolinium (Gd) performance. These parameters show that present magnetic materials are prospective for applications.

中文翻译：

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溶胶-凝胶法合成室温制冷材料La0.8-xSr0.2SmxMnO3(0≤x≤0.2)及其磁热效应研究

摘要 钙钛矿型锰氧化物制备简单、成本低、结构稳定，在低磁场条件下具有巨大的室温磁制冷潜力。本文采用溶胶-凝胶法制备了一系列多晶纳米材料La0.8-xSr0.2SmxMnO3(x = 0,0.05,0.1,0.15,0.2)。XRD图谱表明样品的晶体结构为菱面体，SEM观察到的表面形貌为椭球体。通过超导量子干涉仪测量磁化强度随温度和外部磁场的变化。通过推导计算，理想的磁参数为最大磁熵变、居里温度和相对冷却功率。最后发现，当Sm3+的掺杂量在0.1~0.15范围内时，居里温度控制在266 K~303 K。在5 T外加磁场下，磁熵变最大可达4.03Jkg-1K-1，室温下最大相对制冷功率达到295.31 J/kg，相当于金属钆 (Gd) 性能的 72.03%。这些参数表明目前的磁性材料具有应用前景。