Inducing High Coercivity in MoS₂ Nanosheets by Transition Element Doping

Abstract

MoS 2 nanosheets were doped with vanadium (V) with a variety of concentrations using a hydrothermal method. Raman, X-ray photoelectron spectroscopy, and electron paramagnetic resonance results indicate the effective substitutional doping in MoS 2 . Without V doping, oxides such as MoO 2 and MoO 3 have been observed, whereas with 5 at% V doping, the oxide disappeared. Magnetic measurements show that room temperature ferromagnetism has been induced by V doping. Magnetization tends to increase with the increased V doping concentration. A very large coercivity up to 1.87 kOe has been observed in 5 at% vanadium doped MoS 2, which may attribute to a combination effect of localized charge transfer between V and S ions, pinning effect due to the in-between defects, stress induced by doping, and shape anisotropy due to two-dimensional nature of MoS 2 ribbons.