Absence of ferromagnetism in VSe₂ caused by its charge density wave phase

2019/07/31 by Adolfo O. Fumega, M. Gobbi, P. Dreher +10 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el

paper · pdf · doi:10.1021/acs.jpcc.9b08868

published as J. Phys. Chem. C 2019, 123, 45, 27802-27810 · polished version, updated acknowledgments

arxiv created 2020/01/15 · arxiv updated 2020/01/16

Abstract

How magnetism emerges in low-dimensional materials such as transition metal dichalcogenides at the monolayer limit is still an open question. Herein, we present a comprehensive study of the magnetic properties of single crystal and monolayer VSe₂, both experimentally and ab initio. Magnetometry, X-ray magnetic circular dichrosim (XMCD) and ab initio calculations demonstrate that the charge density wave in bulk stoichiometric VSe_2.0 causes a structural distortion with a strong reduction in the density of sates at the Fermi level, prompting the system towards a non-magnetic state but on the verge of a ferromagnetic instability. In the monolayer limit, the structural rearrangement induces a Peierls distortion with the opening of an energy gap at the Fermi level and the absence of magnetic order. Control experiments on defect-induced VSe_2-δ single crystals show a breakdown of magnetism, discarding vacancies as a possible origin of magnetic order in VSe₂.

Cited by

• Tuning competing electronic phases in monolayer VSe₂ via interface hybridization