Continuous Electrical Manipulation of Magnetic Anisotropy and Spin Flopping in van der Waals Ferromagnetic Devices

TL;DR

This paper demonstrates a method to continuously tune magnetic anisotropy in layered Fe$_5$GeTe$_2$ using gating and temperature, enabling new spintronic functionalities through a controllable spin-flop transition.

Contribution

It introduces a gate-tunable magnetic anisotropy transition in ferromagnetic materials, allowing continuous control of magnetic easy axis orientation for advanced spintronic devices.

Findings

Magnetic anisotropy transitions from out-of-plane to in-plane via gating.

Continuous rotation of magnetic easy axis observed.

Potential for new spintronic functionalities through anisotropy control.

Abstract

Controlling the magnetic anisotropy of ferromagnetic materials plays a key role in magnetic switching devices and spintronic applications. Examples of spin-orbit torque devices with different magnetic anisotropy geometries (in-plane or out-of-plane directions) have been demonstrated with novel magnetization switching mechanisms for extended device functionalities. Normally, the intrinsic magnetic anisotropy in ferromagnetic materials is unchanged within a fixed direction, and thus, it is difficult to realize multifunctionality devices. Therefore, continuous modulation of magnetic anisotropy in ferromagnetic materials is highly desired but remains challenging. Here, we demonstrate a gate-tunable magnetic anisotropy transition from out-of-plane to canted and finally to in-plane in layered Fe$_5$GeTe$_2$ by combining the measurements of the angle-dependent anomalous Hall effect and magneto-optical Kerr effect with quantitative Stoner-Wohlfarth analysis. The magnetic easy axis continuously rotates in a spin-flop pathway by gating or temperature modulation. Such observations offer a new avenue for exploring magnetization switching mechanisms and realizing new spintronic functionalities.