Anisotropic and reversible magnetocaloric effects of the Y-type hexaferrite Sr2Zn2Fe12O22 single crystal

Abstract

Single-crystal Sr2Zn2Fe12O22 (SZFO) Y-type hexaferrite is synthesized using the flux method. Anisotropic magnetocaloric effects (MCEs) are displayed across a wide temperature range from 2 to 400 K. Notably, an inverse MCE phenomenon is observed in the ab-plane, and the value of maximum magnetic entropy change (−ΔSMmax) is −3.21 J/kg K at 24 K under a 50 kOe magnetic field change (ΔH). Across the temperature range of 200–400 K, the c-axis orientation exhibits a table-like conventional MCE. Large refrigerant capacities (RCs) calculated near room temperature are 215.43 J/kg (ab-plane) and 194.80 J/kg (c-axis) at ΔH = 50 kOe, respectively. In addition, SZFO single crystals exhibit reversible MCEs with negligible thermal and magnetic hysteresis in both orientations. The present results highlight the potential application of SZFO in broad-temperature-range multifunctional magnetic refrigeration.