Width-dependent structural stability and magnetic properties of monolayer zigzag MoS₂ nanoribbons

First-principles study based on density functional theory has been employed to investigate width-dependent structural stability and magnetic properties of monolayer zigzag MoS₂ nanoribbons (ZZ-MoS₂ NRs). The width N = 4-6 (the numbers of zigzag Mo-S chains along the ribbon length) are considered. The results show that all studied ZZ-MoS₂ NRs are less stable than two-dimensional MoS₂ monolayer, exhibiting that a broader width ribbon behaves better structural stability and an inversely proportional relationship between the structural stability (or the ribbon with) and boundary S-Mo interaction. Electronic states imply that all ZZ-MoS₂ NRs exhibit magnetic properties, regardless of their widths. Total magnetic moment increases with the increasing width N, which is mainly ascribed to the decreasing S-Mo interaction of the two zigzag edges. In order to confirm this reason, a uniaxial tension strain is applied to ZZ-MoS₂ NRs. It has been found that, with the increasing tension strain, the bond length of boundary S-Mo increases, at the same time, the magnetic moment increases also. Our results suggest the rational applications of ZZ-MoS₂ NRs in nanoelectronics and spintronics.