Sulfur-vacancy-tunable interlayer magnetic coupling in centimeter-scale MoS2 bilayer

Endowing bilayer transition-metal dichalcogenides (TMDs) with tunable magnetism is significant to investigate the coupling of multiple electron degrees of freedom (DOFs). However, effectively inducing and tuning the magnetic interaction of bilayer TMDs are still challenges. Herein, we report a strategy to tune the interlayer exchange interaction of centimeter-scale MoS2 bilayer with substitutional doping of Co ion, by introducing sulfur vacancy (V-S) to modulate the interlayer electronic coupling. This strategy could transform the interlayer exchange interaction from antiferromagnetism (AFM) to ferromagnetism (FM), as revealed by the magnetic measurements. Experimental characterizations and theoretical calculations indicate that the enhanced magnetization is mainly because the hybridization of Co 3d band and V-S-induced impurity band alters the forms of interlayer orbital hybridizations between the partial Co atoms in upper and lower layers, and also enhances the intralayer FM. Our work paves the way for tuning the interlayer exchange interaction with defects and could be extended to other two-dimensional (2D) magnetic materials.

Automated summary

In this study, a strategy to tune the interlayer exchange interaction of a centimeter-scale MoS2 bilayer by introducing Co ion substitution and sulfur vacancy modulation is reported. The transformed magnetic interaction from antiferromagnetism to ferromagnetism is confirmed through experimental characterization and theoretical calculations, showing enhanced magnetization due to altered interlayer orbital hybridizations and intralayer ferromagnetism. This work opens up new possibilities for manipulating interlayer exchange interactions with defects in two-dimensional magnetic materials.