Proximity-induced ferromagnetism and chemical reactivity in few layers VSe2 heterostructures

TL;DR

This study investigates the magnetic and chemical properties of VSe2 heterostructures, revealing that ferromagnetism is not intrinsic but can be induced via coupling with Fe layers, and explores interfacial reactivity.

Contribution

It provides experimental evidence that intrinsic ferromagnetism in VSe2 is absent and demonstrates how ferromagnetism can be induced through heterostructure formation with Fe.

Findings

Native VSe2 lacks intrinsic ferromagnetism.

Ferromagnetism can be induced at room temperature via Fe coupling.

Interfacial chemistry influences magnetic coupling.

Abstract

Among Transition-Metal Dichalcogenides, mono and few-layers thick VSe2 has gained much recent attention following claims of intrinsic room-temperature ferromagnetism in this system, which have nonetheless proved controversial. Here, we address the magnetic and chemical properties of Fe/VSe2 heterostructure by combining element sensitive absorption spectroscopy and photoemission spectroscopy. Our x-ray magnetic circular dichroism results confirm recent findings that both native mono/few-layer and bulk VSe2 do not show any signature of an intrinsic ferromagnetic ordering. Nonetheless, we find that ferromagnetism can be induced, even at room temperature, after coupling with a Fe thin film layer, with antiparallel alignment of the moment on the V with respect to Fe. We further consider the chemical reactivity at the Fe/VSe2 interface and its relation with interfacial magnetic coupling.