Luminescence of BaCl2:Eu2+ particles dispersed in the NaCl host excited by synchrotron radiation

BaCl2:Eu2+ microcrystals embedded in the NaCl host have been obtained in the NaCl-BaCl2(1 mol%)-EuCl3(0.02 mol%) crystalline system. The influence of the annealing conditions on the formation of such particles has been studied. In particular, long-term annealing (at 200 °С during 100 h) promotes the microcrystals formation in the NaCl-BaCl2-Eu crystalline system. The subsequent heat treatment (annealed at 600 °С during 72 h and quenched to room temperature) is shown to lead to the destruction of the majority of these particles. The luminescent-kinetic properties of BaCl2:Eu2+ microcrystals have been studied upon the ultra-violet excitation by the synchrotron radiation. The X-ray excited luminescence has been measured in order to estimate the distribution of europium ions between microcrystals and the NaCl host. The excitation mechanisms of Eu2+ ions in the NaCl-BaCl2-Eu crystalline system are discussed.

► The formation of BaCl2:Еu2+ microcrystals of 1-100 μm size embedded in the NaCl host is revealed. ► Annealing at 600 °C leads to the destruction of significant number of embedded microcrystals. ► The luminescent parameters of microcrystals is similar to ones of single crystal analogs.