O Plasma Treatment Enhanced Room Temperature Ferromagnetism in MoS2

Abstract

MoS 2 is a typical two-dimensional material with promising optical and electrical properties. The realization of ferromagnetism in MoS 2 is important for its applications in semiconductor spintronics. A facile technique should be developed to induce the ferromagnetism in MoS 2 , and the possible extrinsic contribution should be avoided. In this paper, flower-like MoS 2 nanostructures were fabricated by the hydrothermal method. X-ray diffraction spectra show the 1 T/2H mixed phases of as-prepared MoS 2 nanostructures, which changes to pure 2H structure after the O plasma treatment. Raman spectra confirm the existence of Mo-O bonding, which is further confirmed by the X-ray photoelectron spectra after the O plasma treatment. Magnetization measurements at 300 K show the weak ferromagnetism in the as-prepared MoS 2 , with saturated ferromagnetic magnetization of 0.0012 emu/g. After the O plasma treatment, the weak ferromagnetism is strongly enhanced with saturated ferromagnetic magnetization of 0.0343 emu/g. First principle calculation has been performed to disclose the possible origin of ferromagnetism. Significant overlapping between the density of states of O and Mo, or O and S has been observed. The magnetic contribution from Mo and S is negligible, while O takes the main role for the enhanced ferromagnetism.

Emerging Enhancement and Regulation Strategies for Ferromagnetic 2D Transition Metal Dichalcogenides

“…Xie et al. [ 9 ] prepared nanoflower‐like MoS 2 by hydrothermal method. Through some characterization methods, it is proved that the structure of MoS 2 changes after O plasma treatment.…”

“…Reproduced with permission. [9] Copyright 2022, Springer US. defects after irradiation is the main reason leading to the change of magnetic properties (Figure 13e-h).…”

“…In addition to obtaining dilute magnetic semiconductors with distinct ferromagnetic properties by introducing magnetic ions to occupy lattice sites with ferromagnetic exchange interactions in the semiconductor, nonmagnetic ion doping can also induce ferromagnetism. Xie et al [9] prepared nanoflower-like MoS 2 by hydrothermal method. Through some characterization methods, it is proved that the structure of MoS 2 changes after O plasma treatment.…”

“…High cost and complex experimental conditions. [8,9,88,89] O/N plasma Electron injection expected to combine diluted magnetic semiconductors, antiferromagnetic semiconductors, and superconductors to form new heterojunctions and explore more new electronic devices. Therefore, there are still many challenges and endless opportunities in the research of magnetic properties of TMD materials.…”

Role of Hydrogen in Suppressing Secondary Nucleation in Chemical Vapor-Deposited MoS2

“…Recent years have seen a strong surge in the research of transition-metal dichalcogenides (TMDs) due to their versatile characteristics such as semiconducting and superconducting nature, sub-nanometer thickness, flexibility, high optical absorbance, high mobilities, spin–orbit coupling, ferromagnetism, , and so forth, making them an attractive choice for electronic, , optoelectronic, , spin, and valleytronic devices. TMDs are a sub-class of two-dimensional (2D) materials, where a transition metal is sandwiched between two chalcogen atoms, forming a three-atom-thick layer with strong intralayer covalent bonds and weak interplanar van der Waals (vdW) bonds, such that the 2D layers have no dangling bonds on the surface, leading to the low density of interface trap states and reduced scattering. , Within the 2D-TMD family, MoS 2 is the most extensively studied material that has been successfully implemented in the demonstration of logic circuits, − RF circuits, , sensors, , memory circuits, and so forth.…”