Propriétés Luminescentes et Résonance Paramagnétique de l'Ion Mn2+ dans les Phosphores Ca(S : Se) : Mn

Abstract

Ca(S:Se) phosphors activated with Mn were synthesized by making use of pure CaS and CaSe powders prepared carefully by chemical procedures. X-ray inspection showed that Vegard's relation is valid in Ca(S:Se) system. Spectral distribution of emission band, excitation spectra and electron spin resonance were measured about these phosphors. Racah parameters of Mn ²⁺ ion and crystal field parameter D q are determined by an analysis of observed excitation peaks. The most fitted value of 10 D q for these phosphors lies between 6100 and 6500 cm ^-1 . The absolute value of their fine structure coupling constant lies between 70 and 77×10 ^-4 cm ^-1 , being nearly independent of CaSe content. The comparison between the values of these two parameters of Ca(S:Se):Mn phosphors and those of Zn(S:Se):Mn phosphors, reported in the previous paper, shows that the Mn ²⁺ –anion bond in the formers contains far less covalency than in the latters.