Magnetism of Single Vacancies in Rippled Graphene

Abstract

Using first-principles calculations, the dependence in the properties of the monovacancy of graphene under rippling controlled by an isotropic strain was determined, with a particular focus on spin moments. At zero strain, the vacancy shows a spin moment of 1.5 μ B that increases to ∼2 μ B when the graphene is in tension. The changes are more dramatic under compression in that the vacancy becomes nonmagnetic when graphene is compressed more than 2%. This transition is linked to the structural changes that occur around vacancies and is associated with formation of ripples. For compressions slightly greater than 3%, this rippling leads to formation of a heavily reconstructed vacancy structure consisting of two deformed hexagons and pentagons. Our results suggest that any magnetism induced by vacancies that occurs in graphene can be controlled by applying strain.

Strain-induced magnetism in MoS2 monolayer with defects

“…Santos et al 22 studied graphene with single vacancy and found tensile-strainenhanced spin moment. In contrast to graphene, V S2 -and V Mo -MoS 2 have no magnetism found till strain induces a semiconductor-metal transition.…”

“…The idea of applying strain arises from the following considerations: first, the magnetism found in the defected graphene may arise partly from an itinerant origin 2,5,22 in which conducting electrons play a role. In this regard, the absence of magnetism in defected MoS 2 is possibly due to the existence of a sizable band gap; secondly, tensile strain has been proven to be efficient in reducing band gap of pristine single-layer MoS 2 (PMoS 2 ) 11,13 and in improving carrier mobility as well 9,12 .…”

Topologically confined states at corrugations of gated bilayer graphene

“…These ripples can lead to interesting electronic [38][39][40], magnetic [41], and chemical properties [42], mostly due to the associated charge inhomogeneity and the changes in hybridization. In fact, folding graphene has been put forward as a way to modify its properties [43][44][45]; also, folded ribbons have been proposed as graphene-based electronic connectors between edges or graphene layers [46].…”

Strain-induced modulation of magnetic interactions in graphene

“…[1][2][3] In recent years the potential to tune the electronic, [4][5][6][7][8][9][10][11][12] transport, 4,[13][14][15][16][17][18] optical, 10,19,20 and magnetic [21][22][23][24][25] properties of graphene systems by applying strain has been explored. The degree to which these properties can be tuned is enhanced by the different types of strain that can be applied.…”