Luminescence of Mn4+ in the orthorhombic perovskite, LaGaO3

Abstract The optical properties of Mn 4+ (3 d 3 ) in the orthorhombic perovskite, LaGaO 3 are investigated. The Mn 4+ energy levels are calculated using the exchange charge model of crystal-field theory. The calculated Mn 4+ 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 D q =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 2 E g → 4 A 2g transition and its vibrational sidebands. A comparative study of the variation in the crystal-field splitting and the Mn 4+ 2 E g energy level position in materials with the perovskite structure is also presented.