Scintillation properties and energy transfer in (GdY)AlO3:Ce3+ perovskites with high Gd content

The scintillation, optical, and photoluminescence properties of yttrium gadolinium aluminum perovskites activated by Ce3+ ions, (Y1− x Gd x )AlO3:Ce3+, were studied. A set of single-crystalline films with Gd content from $x = 0$ to 1 was grown by the liquid phase epitaxy. At higher Gd content, the bidirectional nonradiative energy transfer (ET) between Ce3+ and Gd3+ ions was observed, and an adequate model that took into consideration the energy migration over the Gd subsystem was suggested. The results decidedly showed that in samples with low Gd content, $x , the ET from Gd3+ to Ce3+ ions prevailed, which increased the light output. However, slow components appeared simultaneously in the scintillation decays. At high Gd concentrations, the nonradiative back ET from Ce3+ to Gd3+ predominated, which resulted in a considerable acceleration of scintillation decays from 28 ns in YAlO3:Ce to less than 2 ns in GdAlO3:Ce, but simultaneously the Ce3+ emission was significantly reduced.