Versatile Electronic and Magnetic Properties of SnSe2 Nanostructures Induced by the Strain

First-principles calculations were employed to explore the electronic and magnetic properties of a two-dimensional (2D) SnSe2 monolayer sheet and its derived one-dimensional (ID) nanoribbons and nanotubes. The results unveiled that the semiconductor metal or metal semiconductor transition can be realized by subtly controlling the strain for all these nanostructures. Surprisingly, without introduction of impurities and the absence of transition metal atoms, a -10% compressive strain can induce magnetic behaviors in SnSe2 armchair nanoribbons and the emerged magnetic moment increases rapidly and linearly with the increase of strain. The magnetism is found to be stemmed from the nonmetallic anionic Se atom at the ribbon edge. The tunable electronic and magnetic properties can be well understood through the analysis of partial charge density distribution and partial density of states. It was found that the direction of applied strain is a determined factor that can affect the energy shift of Se p orbital, leading to different composition of the states near the Fermi level. Finally, the stabilities of these SnSe2 nanostructures were evaluated for the possibility of experimental realizations. We believe that our results will provide useful information for their potential applications in electromechanical nanodevices, which will stimulate further experimental and theoretical investigations in this field.