Effect of crystal structure upon the luminescence of manganese-activated lithium titanate

Abstract

At -195°C, the photoluminescence spectrum of Li2TiO 3: Mn phosphors has been found to consist of nine narrow bands in the red. This is typical of phosphors activated by Mn+4 ions. The phosphorescence at -195°C decays exponentially with a lifetime of 1.1 milliseconds. Disordering of the cation arrangement in the Li 2TiO3 structure by addition of MgO or heat treatment results in a disappearance of the fine structure in the emission and its replacement by a single broad band. The phosphorescence consists of a number of faster superimposed exponential decays. These results are interpreted qualitatively in terms of the changes in interaction of the states of the Mn+4 ion with the crystal.