Study of the magnetocaloric effect in single-phase antiferromagnetic GdMnO₃

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.