A study of the structure of the Cr³⁺-vacancy centre in MgO using EPR and optical spectra

Abstract

The relationships among the structure parameter of the Cr3+-vacancy centre, the EPR parameter D and the splitting Delta E(2E) of the 2E state in MgO:Cr3+ are established according to third-order perturbation formulae and the SCF d orbit of a Cr3+ ion. By using these, the structure parameter of the Cr3+-Vc centre is determined quantitatively from the EPR and optical spectra data, and the results show that the displacement Delta R of the anion O2- along the (001) axis is Delta R=0.056+or-0.004 AA. This method would be effective in determining the structure parameter of other Mn+-Vc centres.