Confinement effect enhanced Stoner ferromagnetic instability in monolayer 1T-VSe<sub>2</sub>
Junyi He, Qing Xie, Gang Xu
Abstract
Abstract Monolayer 1T-VSe 2 has been reported as a room-temperature ferromagnet. In this work, by using the first-principles calculations, we unveil that the ferromagnetism in monolayer 1T-VSe 2 is originated from its intrinsic huge Stoner instability enhanced by the confinement effect, which can eliminate the interlayer coupling, and lead to a drastic increase of the density of states at the Fermi level due to the presence of Van Hove singularity. Our calculations also demonstrate that the Stoner instability is very sensitive to the interlayer distance. These results provide a useful route to modulate the nonmagnetic to ferromagnetic transition in few-layers or bulk 1T-VSe 2 , which also shed light on the enhancement of its Curie temperature by enlarging the interlayer distance.