Influence of Mg-codoping, non-stoichiometry and Ga-admixture on LuAG:Ce scintillation properties
| Autor: | P. Prusa, C. Guguschev, Alena Beitlerova, Vladimir Babin, Dalibor Pánek, Kei Kamada, Romana Kucerkova, Lubomír Havlák, J. Pejchal, P. Zemenova, Jan Bárta, Akira Yoshikawa, Tomáš Parkman |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Diffraction Scintillation Materials science Valence (chemistry) Energy transfer Organic Chemistry Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences 7. Clean energy Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Inorganic Chemistry 0103 physical sciences Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Luminescence Garnet crystals Spectroscopy Stoichiometry |
| Zdroj: | Optical Materials. 86:213-232 |
| ISSN: | 0925-3467 |
| DOI: | 10.1016/j.optmat.2018.10.015 |
| Popis: | This study focused on the influence of Mg codoping, non-stoichiometry and Ga-admixture on the scintillation and luminescence characteristics of Ce-doped lutetium-aluminum garnet crystals (LuAG), the stability of the Ce valence and the role of defects. For the Ce-doped LuAG samples, codoping of Mg at a concentration around 300 ppm led to improvement of overall scintillation efficiency, which is in accordance with previous studies and can be attributed to an alternative scintillation mechanism involving Ce4+ stabilized by Mg2+. Very significant improvement of the overall scintillation efficiency (almost a factor of 2) and exceptionally high light yield when compared to the stoichiometric sample was observed for the Ce0.2% Mg 300 ppm sample grown from the melt with 3 atomic % Al-rich nonstoichiometry. This was explained by enhanced energy transfer towards the Ce3+ luminescence center via defect levels induced by non-stoichiometry. The highest Mg concentration brings additional slow components to the scintillation decay. Very similar trends were observed for the Ga-admixed LuGAG, but the defect luminescence was strongly suppressed. Suppression of this competitive luminescence channel led to further improvement of the overall scintillation efficiency. Interestingly, X-ray diffraction has shown that the crystals contain two or even three garnet phases with very close compositions. |
| Databáze: | OpenAIRE |
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