Strain-improved electronic and magnetic properties of V-, Cr-, Mn- and Fe-doped α- and β-tellurene

The effect of biaxial strain on the electronic and magnetic properties of V-, Cr-, Mn- and Fe-doped alpha- and beta-tellurene was researched by the first-principles calculations. Under the strains from -6% to 6%, the bandgap of alpha- and beta-tellurene changes obviously, and the strained alpha- and beta-tellurene systems keep the characteristic of nonmagnetic semiconductors. Unstrained alpha- and beta-tellurene structures doped with V, Cr, Mn and Fe atoms show different electronic properties and magnetic moments. The transition metal (TM) doped tellurene structures undergo the transformations with magnetic half-metallic-magnetic metal-magnetic semiconductor under -6% to 6% strains. Except for Mn-doped beta-tellurene, the magnetic moments of other TM-doped tellurene have little change under different strains. The magnetic moment of Mn-doped beta-tellurene suddenly decreases from 5 mu(B) to 2 mu(B) under the -4% and -6% strains. This is mainly due to decreasing TM-Te bond lengths and increasing interaction between TM and Te atoms under the large strains. In conclusion, TM doping and strain-engineering can effectively inject magnetic and change the magnetic moment and electronic properties of tellurene. These results have important guiding significance for the further experimental research of tellurene-based spintmnics and magnetic devices.