Indexed on: 22 Nov '17Published on: 11 Oct '17Published in: ECS journal of solid state science and technology : JSS
The optical properties of Mn4+ (3d3) in the double perovskites, La2LiSbO6 and La2MgTiO6, are investigated. The Mn4+ energy levels are calculated using the exchange charge model of crystal-field theory and compared with the experimental spectroscopic data. A comparative study of the optical properties of Mn4+ in the perovskite structure shows that energy of the 2Eg-> 4A2g emission transition is determined by octahedral site distortion. The greater is the site distortion, the lower is the Mn-O covalent interaction and the higher is the energy of the 2Eg-> 4A2g emission transition. The work provides guidelines for the development of deep red emitting phosphors for agricultural (horticultural) applications.