Magnetic Texture in Insulating Single Crystal High Entropy Oxide Spinel Films

TL;DR

This study demonstrates that high entropy oxide spinel films can be synthesized with smooth surfaces and tunable magnetic properties at room temperature, advancing their potential for spintronic applications.

Contribution

It introduces entropy-assisted synthesis of single crystal high entropy oxide spinel films with controllable magnetic textures and anisotropy.

Findings

Films exhibit smooth surfaces and high resistivity.

Magnetic responses can be manipulated by strain.

Room temperature magnetic anisotropy is achieved.

Abstract

Magnetic insulators are important materials for a range of next generation memory and spintronic applications. Structural constraints in this class of devices generally require a clean heterointerface that allows effective magnetic coupling between the insulating layer and the conducting layer. However, there are relatively few examples of magnetic insulators which can be synthesized with surface qualities that would allow these smooth interfaces and precisely tuned interfacial magnetic exchange coupling which might be applicable at room temperature. In this work, we demonstrate an example of how the configurational complexity in the magnetic insulator layer can be used to realize these properties. The entropy-assisted synthesis is used to create single crystal (Mg0.2Ni0.2Fe0.2Co0.2Cu0.2)Fe2O4 films on substrates spanning a range of strain states. These films show smooth surfaces, high resistivity, and strong magnetic responses at room temperature. Local and global magnetic measurements further demonstrate how strain can be used to manipulate magnetic texture and anisotropy. These findings provide insight into how precise magnetic responses can be designed using compositionally complex materials that may find application in next generation magnetic devices.