Magnetic structure and magnetocaloric properties of SrGd2O4 prepared by solid-state method

The preparation of SrGd2O4 was carried out by the solid-state route and its structural, magnetic, magnetocaloric properties have been investigated. The compound formation was confirmed using X-ray diffraction analysis. The elaborated sample annealed at 1300 ? in the air for 24 h, crystallizes in the orthorhombic structure with Pnma space group. Combining different models, a detailed analysis of the magnetic phase transitions in the SrGd2O4 compound has been performed. At 2.8 K, the phase transition from the AFM (Anti-ferromagnetic) state to the PM (Para-magnetic) state is 2nd order. Furthermore, the magnetization process exhibits a large magnetocaloric effect (MCE). The maximum magnetic entropy change (delta S-M) near 2.8 K and refrigerant capacity (RCP) are 20.39 J. Kg(-1). K-1 and 163.12 J. Kg(-1), respectively, for a field change of 0-5 T. With negligible thermal and field hysteresis, SrGd2O4 can be considered as a cryogenic refrigerant material. A phenomenological model is now used to comprehend the MCE behavior of this sample. The exponents delta (delta) is properly revealed to be nearby those of the tricritical M-F-M (Mean-Field-Model) value. This simply reflects the existence of an AFM long-range order in our sample.

Automated summary

The preparation, structural, magnetic, and magnetocaloric properties of SrGd2O4 were investigated. The compound formation was confirmed by X-ray diffraction analysis. The analysis of magnetic phase transitions revealed a second-order transition from AFM to PM state at 2.8 K. The sample exhibited a large magnetocaloric effect, making it a potential cryogenic refrigerant material. Furthermore, a phenomenological model was used to understand the magnetocaloric behavior.