The electronic structures and absorption spectra of the perfect MgAl2O4 spinel and the MgAl2O4 containing various vacancies were studied by using density functional theory code. The optical transition models induced by oxygen vacancy were predicted. The results showed that the absorption peak at 5.3eV was due to the neutral oxygen vacancy VO0. Both 3.2 and 4.75eV peaks were attributed to the 1+ charged oxygen vacancy, VO+. Moreover, the absorption spectra also indicated that the experiment observed red-shift in UV transparent spectra of nano-ceramic MgAl2O4 was induced by the various colour centers of oxygen vacancies.

First-Principles Study on the Effects of Point Vacancies on the Spectral Properties of MgAl2O4. S.Jiang, T.Lu, J.Zhang, J.Chen: Solid State Communications, 2011, 151[1], 29-32