Stable ScS2 nanostructures with tunable electronic and magnetic properties

• Two 2D single-layer H-ScS2 and T-ScS2 nanocrystals are demonstrated as free-standing stable.
• Single-layer T-ScS2 remains nonmagnetic and metallic as bulk 1T-ScS2, while single-layer H-ScS2 becomes ferromagnetic and semiconducting from nonmagnetic and metallic bulk 2H-ScS2.
• ScS2 1D nanoribbons exhibit decreased band gap and magnetic moment compared with 2D single-layer H-ScS2.

The layered ScS2 nanostructures are investigated by the first-principles calculations. Single-layer 2D H-ScS2 and T-ScS2 are demonstrated as free-standing stable by phonon spectrum. In addition, their electronic structures and magnetic properties differ from the bulk counterparts and depend on crystal structure types. For example, single-layer H-ScS2 becomes ferromagnetic and semiconducting from nonmagnetic and metallic bulk 2H-ScS2. More interestingly, the electronic structures and magnetic properties of ScS2 can be further modulated from 1D nanoribbons. The present calculations explore novel low-dimensional ScS2 nanostructures as promising candidates of electronic and magnetic devices.