Synergetic Effect of Substitutional Dopants and Sulfur Vacancy in Modulating the Ferromagnetism of MoS₂ Nanosheets

Abstract

The activation and modulation of the magnetism of MoS2 nanosheets are critical to the development of their application in next-generation spintronics. Here, we report a synergetic strategy to induce and modulate the ferromagnetism of the originally nonmagnetic MoS2 nanosheets. A two-step experimental method was used to simultaneously introduce substitutional V dopants and sulfur vacancy (Vs) in the MoS2 nanosheet host, showing an air-stable and adjustable ferromagnetic response at room temperature. The ferromagnetism could be modulated by varying the content of Vs through Ar plasma irradiation of different periods, with a maximum saturation magnetization of 0.011 emu g–1 reached at the irradiation time of 6 s (s). Experimental characterizations and first-principles calculations suggest that the adjustable magnetization is attributed to the synergetic effect of the substitutional V dopants and Vs in modulating the band structure of MoS2 nanosheets, resulting from the strong hybridization between the V 3d state and the Vs-induced impurity bands. This work suggests that the synergetic effect of substitutional V atoms and Vs is a promising route for tuning the magnetic interactions in two-dimensional nanostructures.

Molecular Beam Epitaxy of Two-Dimensional Vanadium-Molybdenum Diselenide Alloys

“…e ., H phase) of the V ions in the 2D alloys. The latter, as predicted by our DFT calculations above, is particularly supported by the similarity between the measured XAS of the 2D V x Mo 1– x Se 2 ( x = 0.26 and 0.55) and that for 2H-VSe 2 . It is noteworthy that our X-ray magnetic circular dichroism (XMCD) measurements at 65 K found no evidence of ferromagnetically coupled V ions in the 2D alloys (see Figure S10), despite some previous DFT studies indicating such magnetic coupling in a similar alloy, V x W 1– x Se 2 …”

Tuning Electrical Conductance in Bilayer MoS2 through Defect-Mediated Interlayer Chemical Bonding

“…Different from the aforementioned approaches, substitutional doping, as one of the most effective and technically mature methods in silicon-based manufacturing processing, has been widely used to tune in-plane physical properties of monolayer and multilayer MoS 2 in a controllable and robust manner. − The effect of doping is not limited to changing the in-plane physical properties. Recent theories suggest that dopants can mediate the interlayer chemical bond of layer-structured material. , Thus, it offers a promising approach to modifying the interlayer coupling and accessing the layer-dependent physical properties in MoS 2 material.…”

Highly Enhanced Defects Driven Room Temperature Ferromagnetism in Mixed-phase MoS2-MoOxFilms

“…However, it got a minimal success since the observed FM is intrinsic or is present because of agglomeration of doped elements is difficult to resolve. Recently, other ways of introducing FM have been tried/suggested in theoretical and experimental studies. − Many groups have performed calculations based on density functional theory (DFT) and reported the FM in MoS 2 due to different intrinsic defects such as sulfur vacancy (V S ), edge dislocations, and so forth. − These theoretical reports predict that the intrinsic defects play an essential role in the ferromagnetic behavior of MoS 2 films. It is reported that the presence of O in MoS 2 plays a crucial role in triggering the FM, but a detailed analysis is missing .…”