Physics of scintillation in REAlO3:Ce3+ (RE=Y, Lu)

The scintillation mechanism model in the complex structure oxide crystals is developed. It describes the creation of excited Ce3+ ion ensemble under ionizing radiation, particularly the last stage of the process, when the excited matrix states interact with Ce3+ ions. It was shown that the mechanism of scintillation is different for Y-and Lu-based crystals. The energy transfer mechanism from self-trapped excitons and holes to Ce3+ ions dominates in Y-based crystal. When Lu ion forms the perovskite matrix host, the consecutive charge transfer process Ce3++h→Ce4+ and Ce4++e→(Ce3+)*→Ce3++hv dominates the creation of excited Ce3+ ions. The developed model describes the scintillation kinetics and light yield changes vs. concentration and temperature. Good agreement of the calculated data and experimental results obtained by different authors is observed.