Effects of 5d transition metals doping on the structural, electronic and magnetic properties of monolayer SnS2

We explore the structural, electronic and magnetic properties of the monolayer SnS2 systems doped with 5d transition metals (TM) atoms X (X = W, Re, Os, Ir, Pt, Au or Hg) using first-principles approach. The formation energies show that these materials can be easily fabricated under the S-rich experimental condition. The spin-polarized phases are more favorable than non spin-polarized phases. The pristine monolayer SnS2 is a nonmagnetic semiconductor with an indirect band gap of 1.579 eV, the 5d TM atoms X (X = W, Re, Os, Ir, Pt, Au or Hg) doped monolayer SnS2 systems have the total magnetic moments of 2, 3, 2, 1, 0, 1, 2 mu(B), respectively, because the octahedral coordinated six S ligands bring in a larger crystal field splitting than exchange splitting onto the 5d TM atoms X. Furthermore, the spin-polarized band structures show that the W, Re or Hg-doped monolayer SnS2 systems are magnetic semiconductors, but the Os, Ir or Au-doped monolayer SnS2 systems are magnetic half-metallic with the wider band gaps of 1.509, 1.632 or 1.383 eV respectively in one of the two spin channels, and thus are useable in spintronic fields.