Abstract The structural, magnetic and magnetocaloric properties of Zn0.5-xNixMg0.5Fe2O4 (x = 0, 0.125, 0.250) ferrites were investigated in detail. The double sintering ceramic process was used to synthesize our samples. The formation of cubic phase of Zn–Ni–Mg ferrite was confirmed through XRD technique. The structural analysis showed that the unit cell volume decreased with increasing Ni content. All compounds exhibited a ferromagnetic-paramagnetic phase transitions of a second order. The entropy change was obtained from the measurements of magnetic isotherms M(H,T) using the Maxwell relation. The maximum magnetic entropy Δ S M max decreases from 1.36 J.Kg−1K−1 (x = 0) to 1.16 J.Kg−1K−1 (x = 0.25) under an applied magnetic field of 5T upon increasing Ni content. Relative cooling power (RCP) was determined as well. It was found to be 107 and 90 J/kg for x = 0 and x = 0.25, respectively. These results make our compounds promising materials for magnetic refrigeration technology.

中文翻译：

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Ni取代对Zn0.5-xNixMg0.5Fe2O4 (x = 0, 0.125 and 0.250)锰矿结构、磁性和磁热性能的影响

摘要 详细研究了Zn0.5-xNixMg0.5Fe2O4 (x = 0, 0.125, 0.250)铁氧体的结构、磁性和磁热性能。双烧结陶瓷工艺用于合成我们的样品。通过XRD技术证实了Zn-Ni-Mg铁氧体立方相的形成。结构分析表明，随着Ni含量的增加，晶胞体积减小。所有化合物都表现出二阶铁磁-顺磁相变。熵变是使用麦克斯韦关系从磁等温线 M(H,T) 的测量中获得的。在 5T 的外加磁场下，随着 Ni 含量的增加，最大磁熵 Δ SM max 从 1.36 J.Kg-1K-1 (x = 0) 降低到 1.16 J.Kg-1K-1 (x = 0.25)。还确定了相对冷却功率 (RCP)。发现对于 x = 0 和 x = 0.25，分别为 107 和 90 J/kg。这些结果使我们的化合物成为磁制冷技术的理想材料。