Current-tunable room temperature ferromagnetism and current-driven phase transitions

TL;DR

This study demonstrates that a charge current can enhance ferromagnetic order and induce phase transitions in a 2D ferromagnet, achieving room temperature ferromagnetism through current control.

Contribution

It reveals that charge currents can boost magnetic ordering and control phase transitions in 2D ferromagnets, contrary to the common assumption of suppression by Joule heating.

Findings

Charge current enhances the Curie temperature above room temperature.

Current controls magnetic phase transitions via an effective magnetic field.

Orbital magnetization mediates the current-induced magnetic effects.

Abstract

It is generally assumed that the application of a charge-current in ferromagnetic metals suppresses their ferromagnetic order through trivial Joule heating. Here, we demonstrate that a charge current can instead enhance magnetic ordering. Using a WTe2/Fe3Ge2Te (FGT) stack as a model system, we show that a charge current flowing in WTe2 controls the ferromagnetic properties and magnetic phase transition of the adjacent FGT via a current-induced effective magnetic-field arising from orbital magnetization. Remarkably, the charge current drives a substantial enhancement of the Curie temperature, boosting it well above room temperature. Furthermore, we show that the charge-current enables controlled tuning of the phase transitions in FGT, which confirms the scaling behaviour of a ferromagnet-paramagnet phase transition. This work provides a pathway for integrating two-dimensional ferromagnets into spintronic functionalities at technologically relevant temperatures and for exploring novel current-driven phenomena in ferromagnetic systems.