The effect of magnetic impurity on the electronical and optical properties of corundum

We have studied the structural, electronical and optical properties of pure α-Al2O3(corundum) and doped with manganese by the first principles calculations method based on the density functional theory (DFT), with generalized gradient approximation (GGA). Obtained results show that α-Al2O3 has an energy gap of 6.3 eV and the substitution of manganese decreases the energy gap so that spin splitting effect is observed. Calculated optical results show that with adding this impurity, reflectivity increase at low energy and decreases at high energy; also static refractive index increases.   Key words: Corundum, manganese, density functional theory (DFT), energy gap, refractive index.