LAUSR

Abstract In this study, density functional theory calculations have been carried out to investigate the electronic structure of Cr2O3 after applying strain and doping vacancy defects. Results indicate that the tensile strain will decrease the gap, while the compressive strain will increase the gap and the planar biaxial strain has more remarkable effects on electronic structure modulation than that of out-of-plane strain. With respect to the vacancy defects, we find both the Cr vacancy and O vacancy will introduce extra energy bands into the band gap, and the Cr vacancy could reduce the band gap remarkably. Cr vacancy leads to conduction band states closing to Fermi level and accounting for a pronounced narrowing band gap. Tensile strain draw conduction band minimum with t2g (dxy, dxz, dyz) and dx2−y2 orbitals nearer to EF, while compressive strain pushes dxy, dxz, dyz and dx2−y2 orbitals away EF, which are responsible for the pronounced narrowing band gap under tensile strain and increasing under compressive strain. In addition, both the strain and vacancy could also influence the magnetic moments of Cr2O3. Interestingly the O vacancy migration appears in Cr2O3 under the planar biaxial tensile strain ranging from 5% to 8%.