Luminescence of Mn4+ in the orthorhombic perovskite, LaGaO3

The optical properties of Mn4+ (3d(3)) in the orthorhombic perovskite, LaGaO3 are investigated. The Mn4+ energy levels are calculated using the exchange charge model of crystal-field theory. The calculated Mn4+ energy levels are in good agreement with the experimental spectroscopic data. The results of our calculations yield the crystal-field splitting and Racah parameters of Dq=1926 cm(-1), B=780 cm(-1) and C=2878 cm(-1), with C/B=3.7. The emission spectrum is assigned on the basis of the zero phonon line corresponding to the E-2(g) -> (4)A(2g) transition and its vibrational sidebands. A comparative study of the variation in the crystal-field splitting and the Mn4+ E-2(g) energy level position in materials with the perovskite structure is also presented. (C) 2016 Elsevier B.V. All rights reserved.