Abstract The study of magnetic measurements and magnetic memory effect was performed on nanocrystalline single-phase powders of GdMnO3 synthesized by the sol–gel method. They were structurally characterized via X-ray diffraction patterns and scanning electron microscopy images. The sol–gel method was coupled with mixing and blending the material powder using two techniques: (a) agate mortar and (b) corn flour. Zero-field cooling and field cooling magnetizations of both types of samples were also investigated thermally, and the susceptibility inverse was used to study the existence of the Griffiths phase. The corn flour technique showed a comparable particle quality and magnetic properties to the traditional mixing technique using an agate mortar. The GdMnO3 exhibited a large magnetocaloric effect with a magnetic entropy change in the range of 24.5–26.9 J/(kg·K) at an applied magnetic field of 5 T at low temperatures. The results surpassed the values reported in the literature by more than 44% at 5 T. The proposed method represents a scalable efficient method to produce a strong candidate material for cryogenic cooling in addition to other applications in electrical machines.

中文翻译：

---

单相反铁磁GdMnO3中的磁热效应研究

摘要 对溶胶-凝胶法合成的 GdMnO3 纳米晶单相粉末进行了磁测量和磁记忆效应研究。它们的结构特征是通过 X 射线衍射图和扫描电子显微镜图像。溶胶-凝胶法与使用两种技术混合和混合材料粉末相结合：（a）玛瑙研钵和（b）玉米粉。还对两种类型的样品的零场冷却和场冷却磁化强度进行了热研究，并使用磁化率倒数来研究格里菲斯相的存在。玉米粉技术显示出与使用玛瑙研钵的传统混合技术相当的颗粒质量和磁性。GdMnO3 表现出大的磁热效应，磁熵变在 24 的范围内。5–26.9 J/(kg·K) 在低温下施加 5 T 的磁场。结果在 5 T 时超过了文献中报告的值 44% 以上。所提出的方法代表了一种可扩展的有效方法，除了电机中的其他应用外，还可以生产用于低温冷却的强大候选材料。