Robust Ferrimagnetism and Switchable Magnetic Anisotropy in High-Entropy Ferrite Film

Ferrimagnetic insulator materials are the enabling technology for the development of next-generation magnetic devices with low power consumption, high operation speed, and high miniaturization capability. To achieve a high-density memory device, a combined realization of robust saturation magnetization (M-s), controllable magnetic anisotropy, and high resistivity (rho) are highly demanded. Despite significant efforts that have been made recently, simultaneously achieving significant enhancements in these properties in a soft magnetic insulator material still remains a great challenge, severely limiting their practical application. Herein, a high-entropy strategy in an ultra-thin spinel ferrite (CrMnFeCoNi)(3)O-4 film is reported that exhibits concurrently a superior saturation magnetization (M-S = 1198 emu cm(-3)), low coercivity (H-C = 90 Oe), and excellent resistivity (rho = 1233 omega cm), as well as switchable magnetic anisotropy. The comprehensive lattice probing and microstructure analysis studies reveal that such desirable ferromagnetic properties originate from the high-quality structurally ordered but compositionally disordered single-crystal epitaxial structure. The switchable magnetic anisotropy demonstrated in the high-entropy ferrite film can be attributed to the new antiferromagnetic rock-salt phase. This work unveils the critical benefits of the high-entropy strategy for magnetic oxide thin films, which opens up new opportunities for the development of high-performance magnetic materials.