Gate-tunable Exchange Bias and Voltage-controlled Magnetization Switching in a van der Waals Ferromagnet

TL;DR

This paper demonstrates voltage-controlled exchange bias and magnetization switching in a van der Waals ferromagnet heterostructure, enabling electrical manipulation of magnetic properties for advanced spintronic applications.

Contribution

It introduces a novel method to electrically modulate exchange bias and magnetization in FGT heterostructures with high stability and tunability.

Findings

Exchange bias magnitude up to 1.4 kOe near 150 K.

Linear dependence of exchange bias on gate voltage.

Successful voltage-controlled magnetization switching.

Abstract

The discovery of van der Waals magnets has established a new domain in the field of magnetism, opening novel pathways for the electrical control of magnetic properties. In this context, Fe3GeTe2 (FGT) emerges as an exemplary candidate owing to its intrinsic metallic properties, which facilitate the interplay of both charge and spin degrees of freedom. Here, the bidirectional voltage control of exchange bias (EB) effect in a perpendicularly magnetized all-van der Waals FGT/O-FGT/hBN heterostructure is demonstrated. The antiferromagnetic O-FGT layer is formed by naturally oxidizing the FGT surface. The observed EB magnitude reaches 1.4 kOe with a blocking temperature (150 K) reaching close to the Curie temperature of FGT. Both the exchange field and the blocking temperature values are among the highest in the context of layered materials. The EB modulation exhibits a linear dependence on the gate voltage and its polarity, observable in both positive and negative field cooling (FC) experiments. Additionally, gate voltage-controlled magnetization switching, highlighting the potential of FGT-based heterostructures is demonstrated in advanced spintronic devices. These findings display a methodology to modulate the magnetism of van der Waals magnets offering new avenues for the development of high-performance magnetic devices.