Speaker
Description
In this work, we continued our research directed on crystallization and investigation of the luminescent and scintillation properties of scintillating screens based on the single crystalline films (SCFs) of Eu3+ doped RAlO3 (R= Tb, Gd, Lu) mixed perovskites [1, 2]. SCFs of the solid solutions of (Tb1-xLux)AP:Ce and Gd1-xTbxAP:Ce, x=0-1.0 perovskites were grown by the liquid phase epitaxy (LPE) method onto YAlO3 (YAP) substrates using the traditional PbO-B2O3 flux. The absorbance, cathodoluminescence (CL), X-ray excited luminescence (RL), photoluminescence (PL) and scintillation properties of these SCFs under α–particles excitation were investigated depending on the perovskite hosts. We have found that the shape of CL, RL and PL spectra, scintillation light yield (LY) and decay kinetics of Eu3+ ions in the RAlO3 (A= Tb, Gd, Lu) SCFs are strongly affected by the local surrounding of dopant depending on the cations-ligands distances in the perovskite hosts. Specifically, the orange emission band at 593 nm dominates in the CL/RL/PL spectra of (Tb,Lu)AP:Eu and (Tb,Gd)AP:Eu SCFs when the red luminescence band at 710 nm prevails in the spectra of LuAP:Eu and YAP:Eu SCFs. The effective Tb3+->Eu3+ and cascade Gd3+ --> Tb3+ --> Eu3+ energy transfer processes has been found in (Tb,Lu)AP and (Gd,Tb)AP lattices, respectively, giving reasons to increasing the efficiency of the Eu3+ luminescence in the perovskite host. We have found also that the highest LY of the CL and X-ray exited luminescence is observed in (Gd0.4-0.5Tb0.5-0.6)AP:Eu and TbAP:Eu SCFs. The LY of the RL in these SCFs is comparable with the LY of the best reference LuAG:Ce and TbAG:Ce SCF samples. For this reason, the SCFs of (Tb,Lu)AP:Eu and (Gd,Tb)AP:Eu perovskites can be considered as promising candidates for the scintillating screens in the microimaging detectors. For the last application, the X-ray absorption ability and LY of (Gd,Lu)AP SCF screens can be also improved by Tb3+ codoping due to the extension of “K-edge engineering” in such mixed perovskite compounds [1] and effective Tb3+ --> Eu3+ energy transfer.
References
[1] F. Riva, F. Riva, P-.A. Douissard, T. Martin, F. Carla, Y.V. Zorenko, C. Dujardin, CrystEngComm, 2016, V.18, P. 608–615.
[2] Yu. Zorenko, V. Gorbenko, T. Zorenko, T. Voznyak, F. Riva, P.A. Douissard, T. Martin, A. Fedorov, A. Suchocki, Ya. Zhydachevski, Journal of Crystal Growth, 2017, V. 457, P. 220-226.
Acknowledgements: The work was performed in the frameworks of Polish NCN 2016/21/B/ST8/ 03200 project and Ministry of Education and Science of Ukraine in frame of SF-20F project.
