Short-range magnetic interaction in a monolayer 1T−VSe2 film revealed by element-specific x-ray magnetic circular dichroism

Abstract

We investigated the intrinsic magnetic properties of the two-dimensional ferromagnetic candidate monolayer $1T\text{\ensuremath{-}}{\mathrm{VSe}}_{2}$ films using x-ray magnetic circular dichroism (XMCD), an element-specific magnetic probe. By performing high-resolution measurements, we succeeded in detecting a clear XMCD signal from the atomically thin $1T\text{\ensuremath{-}}{\mathrm{VSe}}_{2}$ films under an external magnetic field. Through manipulation of the x-ray incidence angle, we were able to disentangle the in-plane and out-of-plane magnetic properties and found a strong magnetic anisotropy. Moreover, magnetic-field- and temperature-dependent XMCD revealed that there is no long-range ferromagnetic ordering even at 6 K, but short-range ferromagnetic and antiferromagnetic interactions between neighboring vanadium ions exist. Such low-temperature magnetic behavior signifies that the monolayer $1T\text{\ensuremath{-}}{\mathrm{VSe}}_{2}$ is on the verge of ferromagnetism, and this fact accounts for the reported ferromagnetism in ${\mathrm{VSe}}_{2}$-based heterostructures.