Luminescence-kinetic properties of LaI3-Ce microcrystals of 1-10 mu m size in NaI-LaI3-Ce system are studied upon 2.5-12 eV excitation using synchrotron radiation. The luminescent properties of cerium centers in the embedded LaI3-Ce microcrystals are revealed to be similar to those for the bulk LaI3-Ce crystals. The mechanisms of cerium centers luminescence excitation in the NaI-LaI3-Ce crystalline system upon excitation in the transparency and fundamental absorption range of NaI and LaI3 matrixes and mechanisms of thermal quenching of cerium ions luminescence in the LaI3 microcrystals are discussed.

Luminescence spectroscopy has been used to determine the parameters of NaI-SrI2-Eu, NaI-SrCl2-Eu, and NaI-BaI2-Eu compounds in the energy range of 3.7–18 eV at 10 and 295 K and investigate the phase formation in these crystalline systems. The NaI-SrI2(1 mol %)-Eu(0.02 mol %) crystalline system has revealed formation of SrI2 microcrystals activated with europium ions and dispersed in the NaI matrix. Formation of SrCl2-Eu2+ microcrystals dispersed in a NaI matrix is observed for NaI-SrCl2(1 mol %)-Eu(0.02 mol %) crystalline system. The mechanisms of aggregation of impurity ions and specific features of luminescence excitation for europium ions in dispersed microcrystals are discussed.