Photoluminescence of exchange-coupled Mo3+ pairs in CsMgCl3

Abstract

The high-resolution luminescence spectra of CsMgCl3 doped with Mo3+ contain bands that are very temperature-sensitive between 5 K and 2 K and that can be assigned to exchange-coupled Mo3+-V-Mo3+ pair centres (V=divalent vacancy). When the host lattice is doped with both Mo3+ and Li+ it is found that pair formation is inhibited and the spectra are principally those of the single Mo3+ cation. Well-resolved multi-line luminescence spectra have been obtained from exchange-coupled Mo3+ pairs in the far red and near infrared. The spectra correlate well with the reported ground-state energy levels of the pairs as calculated from EPR measurements.