Magnetic properties of atomic 3d transition-metal chains on S-vacancy-line templates of monolayer MoS2: effects of substrate and strain
The unique tri-layered atomic structure of MoS2 monolayer is in favor of the formation of sulfur vacancy line (SVL) as confirmed by both theoretical and experimental studies. This defect could be used as a template to accommodate atomic metal chains, which is an interesting research topic in recent years. In this work, we studied the magnetic properties of atomic 3d transition-metal (V, Cr, Mn and Fe) chains adsorbed along SVL of monolayer MoS2 using first-principles calculations. All atomic transition-metal (TM) chains can adsorb stably with large binding energies. The magnetic orders and exchange interactions of 3d transition-metal chains are dramatically influenced by MoS2 substrate. The magnetic ground state of V and Cr chains remain unchanged anchoring on MoS2, however the magnetic interactions are weakened compared to their free standing cases. Mn and Fe chains show transitions from ferromagnetic (FM) coupling in freestanding chain to antiferromagnetic (AFM) coupling on the SVL of MoS2. The magnetic coupling in atomic transition metal chains is mediated by Mo atoms at the vicinity of atomic chains, which is governed by the combination of through-bond and through-space interactions. It is found that through-bond coupling is dominated in FM V/MoS2 and through-space coupling is dominated in the AFM state of Cr/MoS2, Mn/MoS2 and Fe/MoS2. The electronic properties, magnetic order and exchange interactions of atomic 3d transition-metal chain on SVL of MoS2 can be tuned by the uniaxial strain applied along chain direction.