LPE growth of single crystalline film scintillators based on Ce3+ doped Tb3-xGdxAl5-yGayO12 mixed garnets

Abstract

The growth of single crystalline films (SCFs) with excellent scintillation properties based on the Tb1.5Gd1.5Al5-yGayO12:Ce mixed garnet at y = 2-3.85 by Liquid Phase Epitaxy (LPE) method onto Gd3Al2.5Ga2.5O12 (GAGG) substrates from BaO based flux is reported in this work. We have found that the best scintillation properties are shown by Tb1.5Gd1.5Al3Ga2O12:Ce SCFs. These SCFs possess the highest light yield (LY) ever obtained in our group for LPE grown garnet SCF scintillators exceeding by at least 10% the LY of previously reported Lu1.5Gd1.5Al2.75Ga2.25O12:Ce and Gd3Al2-2.75 Ga3-2.25O12:Ce SCF scintillators, grown from BaO based flux. Under α-particles excitation, the Tb1.5Gd1.5 Al3Ga2O12:Ce SCF show LY comparable with that of high-quality Gd3Al2.5Ga2.5O12:Ce single crystal (SC) scintillator with the LY above 10,000 photons/MeV but faster (at least by 2 times) scintillation decay times t1/e and t1/20 of 230 and 730 ns, respectively. The LY of Tb1.5Gd1.5Al2.5Ga2.5O12:Ce SCFs, grown from PbO flux, is comparable with the LY of their counterparts grown from BaO flux, but these SCFs possess slightly slower scintillation response with decay times t1/e and t1/20 of 330 and 990 ns, respectively. Taking into account that the SCFs of the Tb1.5Gd1.5Al3-2.25Ga2-2.75O12:Ce garnet can also be grown onto Ce3+ doped GAGG substrates, the LPE method can also be used for the creation of the hybrid film-substrate scintillators for simultaneous registration of the different components of ionization fluxes.