Magnetism in MoS2 induced by proton irradiation

Abstract

Molybdenum disulphide, a diamagnetic layered dichalcogenide solid, is found to show magnetic ordering at room temperature when exposed to a 2 MeV proton beam. The temperature dependence of magnetization displays ferrimagnetic behavior with a Curie temperature of 895 K. A disorder mode corresponding to a zone-edge phonon and a Mo valence higher than +4 has been detected in the irradiated samples using Raman and x-ray photoelectron spectroscopy, respectively. The possible origins of long-range magnetic ordering in irradiated MoS2 samples are discussed.

Interactions and superconductivity in heavily doped MoS2

“…5,6 Metallic behavior can be induced, also as in graphene, by means of electric field effects or by doping, and the corresponding Fermi surface is typically made up of inequivalent Fermi pockets, [7][8][9][10][11][12] defining a valley degree of freedom which is strongly entangled with the spin degree of freedom, 13 and it can be further controlled and manipulated, opening promising perspectives for spintronics. At high carrier concentrations (n ∼ 10 14 cm −2 ), and in the presence of high-κ dielectrics, MoS 2 has also been shown to undergo a superconducting transition, with a doping-dependent critical temperature T c (n) which exhibits a maximum as a function of n and drops to zero at sufficiently large values of n. 14,15 A ferromagnetic behavior has also been reported in MoS 2 , [16][17][18][19] and it has been related to edges or to the existence of defects. 20,21 The magnetic properties of MoS 2 nanoribbons indicate that the electron-electron interactions are non-negligible.…”

Two-dimensional inorganic analogues of graphene: transition metal dichalcogenides

“…Lithiated MoS 2 prepared by soaking the bulk MoS 2 in n-butyl lithium also exhibits room-temperature ferromagnetism [87]. Upon exposure to a 2 MeV proton beam, MoS 2 exhibits room-temperature magnetic ordering and the temperature dependence of magnetization displays ferrimagnetic behaviour with a Curie temperature of 895 K. Proton irradiation can induce formation of isolated vacancies, vacancy clusters, edge states and reconstructions of the lattice which may give rise to room-temperature magnetism [88]. Graphene-like MoS 2 is ferromagnetic at room temperature with the fieldcooled (FC) and the zero-field-cooled (ZFC) magnetization diverging from about 300 K [28,89].…”

Valley- and spin-filter in monolayer MoS2

“…These features provide us a new way to generate spinand valley-polarized current in monolayer MoS 2 . Recent studies stated that a ferromagnetic behavior [15][16][17][18][19][20][21][22] and a superconducting [23][24][25][26] transition can be occurred in MoS 2 sheet. Also, the single-layer and multi-layer MoS 2 can be n-or p-type doped on generating desirable charge carriers [7,8].…”