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The glass‐ceramics (GC) of gadolinium aluminum gallium garnets with the expected composition of Gd3Al3Ga2O12:Ce and Gd3Al3Ga2O12:Ce,Be (GAGG:Ce and GAGG:Ce,Be, respectively) are fabricated by crystallization from the Gd2O3–Al2O3–Ga2O3–CeO2–SiO2–BeO (Gd:Ga:Al ratio is close to 3:2:3) glasses. The influence of Be2+ co‐doping (including doping level) on the luminescent properties of the GAGG is demonstrated. In particular, Be co‐doping results in the suppression of the Ce3+‐related radioluminescence (RL) and as a consequence, the light yield is lowered as well. The conclusion is made that Be2+ creates effective electron or hole trapping centers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electron and hole trapping centers were observed in the molybdenum doped zinc oxide rods. • Electron trapping centers were mostly molybdenum-based. • Holes were trapped at oxygen complexes. • Exciton- and defect-related emission bands appear suppressed after X-ray irradiation. • Zinc vacancies participated in the charge trapping processes. Peculiarities of the point defects creation under X-ray irradiation and the influence of Mo doping in ZnO powders of nano- and microrods fabricated by the hydrothermal growth method (as-grown and annealed in air) were studied in detail. Correlated experiments of X-ray diffraction, X-ray photoelectron spectroscopy, electron paramagnetic resonance, photo- and radioluminescence as well as thermally stimulated luminescence allowed us to trace the effect of the molybdenum inclusion on the phase purity of synthesized materials and the role of Mo in the creation of X-ray induced point defects. Oxygen-based hole trapping centers (most probably involving interstitial oxygen) as well as Mo5+-based electron trapping centers were observed and their thermal stabilities were studied. Some amount of the hole trapping centers seemed to be directly connected with the creation of Mo5+. Zinc vacancies and the Mo5+ centers up to some extent were assumed to act as recombination centers for the holes released from the hole trapping centers. The X-ray irradiation also affects the luminescence properties of the ZnO:Mo samples – the intensity of the luminescence bands in general becomes weaker. [ABSTRACT FROM AUTHOR]

Luminescence and scintillation characteristics of Mg2+-codoped (Lu x Gd 3-x)Al 2.4 Ga 2.6 O 12 :Ce (x = 0.2–0.8) garnet crystals grown by the micro-pulling down method are investigated. The Ce3+ 5d 1 → 4f luminescence is blue-shifted with increasing Lu content due to the decrease in crystal field splitting of the 5 d levels. With increasing Lu content, the shortening of scintillation decay time accompanied with a decrease of LY value as measured at room temperature can be explained by thermal ionization of the Ce3+ 5d 1 excited state. Co-doping with Mg2+ results in the shortening of scintillation decay time, the reduction of LY value and afterglow intensity. At low temperature the radioluminescence quenching is observed in correlation with large thermoluminescence peaks, which can be attributed to the localization of electrons at intrinsic shallow traps. • Luminescence and scintillation of (Lu,Gd) 3 Al 2.4 Ga 2.6 O 12 :Ce, Mg crystals are investigated. • Temperature dependence of photo-and radioluminescence are presented. • Luminescence quenching above RT can be caused by thermal ionization. • Afterglow and low-temperature TL characteristics are investigated. [ABSTRACT FROM AUTHOR]