Crystal field studies of the Mn4+ energy levels in the perovskite, LaAlO3

The electronic energy levels of the Mn4+ (3d(3)) ion in the rhombohedral perovskite, LaAlO3, have been calculated using the exchange charge model of crystal field theory. The calculated Mn4+ energy levels are in good agreement with the experimental spectra that have been presented in the literature. The results of our calculations yield the crystal field splitting and Racah parameters of Dq = 2123 cm(-1), B = 695 cm(-1) and C = 2941 cm(-1), with C/B = 4.2. A cross-cutting comparative study of the variation in the crystal field splitting and the Racah parameters of the octahedrally coordinated Mn4+ ion in a series of materials with the perovskite structure is also presented. We have also introduced a dimensionless parameter (beta(1)) which quantifies the nephelauxetic effect and predicts the energy of the E-2(g) -> (4)A(2g) emission transition in the perovskites. (c) 2013 Elsevier B.V. All rights reserved.