Structure, electric, elastic and optical properties of Mn2+-doped MgAl2O4 spinel with/without an O-vacancy

Theoretical studies of Mg(1−x)MnxAl2O(4−y)(x=0,0.125,0.25,0.375,0.5)(y=0,1) crystal structures are presented using density functional theory (DFT). Both the local density approximation and the generalized gradient approximation are used for the exchange-correlation potential. The results of lattice constants, band lengths and populations, density of states, band structures, elastic constants, real and imaginary parts of dielectric constants, and absorption coefficients for these ten crystal structures are obtained, and compared with experimental and computational results in detail. One O-vacancy deficiency decreases the lattice constant and the band gap, but it almost does not impact on elastic and optical properties. Mn2+ substituting-doping impurities influence on every property concerned. The transition metal ions promote the mechanical index, and induce linearly increasing in the optical absorption of both energy and intensity. The calculation results provide basic and meaningful information for further understanding, design and preparation of Mn2+ composition-dependent MgAl2O4 transparent materials in the UV region.