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The luminescence and scintillation properties of Ce3+-doped Gd 3 (Al 5-x Sc x)O 12 (x = 1, 1.5, 2, 2.5, 3) garnet crystals grown by the floating zone method were investigated. With increasing Sc content, the Ce3+ 5d 1 → 4f luminescence was blue shifted due to a decrease in 5d 1 -5d 2 crystal field splitting (Δ 12) of the 5d e doublet state. The Sc content showed a strong influence on purity of garnet phase in the Gd 3 (Al 5-x Sc x)O 12 :Ce crystals. The presence of secondary phase (perovskite and/or α-Al 2 O 3) results to a poor transparency and a lower light yield (LY) value. The Gd 3 Al 3 Sc 2 O 12 :Ce crystal exhibited pure garnet phase, highest quantum yield (∼76 %) and transmittance (∼80 %), and highest LY value (6,850 photons/MeV at 662 keV γ rays) among the studied samples. Above RT, a decrease of radioluminescence (RL) yield occurs for all samples due to the thermal ionization process. A decrease of the RL yield at low temperature observed in correlation with the intense thermoluminescence peaks can be explained by the localization of electrons at intrinsic shallow traps. • Luminescence and scintillation characteristics of Gd 3 (Al 5-x Sc x)O 12 :Ce crystals are investigated. • Temperature dependence of radioluminescence yield is measured in 10–350 K range. • Gd 3 Al 3 Sc 2 O 12 :Ce shows highest quantum yield and light yield. • Thermoluminescence and low-temperature afterglow are investigated. [ABSTRACT FROM AUTHOR]

Yttrium pyrosilicate (Y 2 Si 2 O 7) single crystals are successfully grown by the floating-zone method with 0.5–10.0% of Ce-doping concentration. X-ray diffraction patterns indicate a single phase of Y 2 Si 2 O 7 without the impurity phase. The series photoluminescence (PL) and scintillation properties are systematically explored in this study, including PL emission, PL decay time, X-ray induced scintillation spectra, X-ray induced scintillation decay time, afterglow profile, and pulse height spectra. Ce-doped Y 2 Si 2 O 7 is presented interesting properties including the intense emission band at 390 nm from Ce3+ 5d-4f transition on both PL emission contour maps as well as X-ray-induced scintillation spectra in all samples. The afterglow level at 20 ms after X-ray irradiation of the Ce-doped YPS is comparable with commercial scintillators such as CdWO4 and Tl-doped CsI. Under 137Cs (662 keV) γ-ray irradiation 137Cs (662 keV), the highest scintillation light yield of Ce-doped Y 2 Si 2 O 7 is reach up to 17,200 ph/MeV for 2.0% Ce-doped sample. • YPS single crystals with Ce-doped of 0.5–10.0 are synthesized by a FZ method. • Samples exhibit PL and scintillation emission at 360–400 nm from the Ce3+ 5d-4f. • The dominant scintillation decay time is 28–33 ns. • The afterglow level at 20 ms after X-ray irradiation is 60–80 ppm. • Under 662 keV γ-ray, scintillation light yield of Ce:YPS is up to 17,200 ph/MeV. [ABSTRACT FROM AUTHOR]

Lutetium pyrosilicate (Lu 2 Si 2 O 7) single crystals were synthesized by using the floating-zone method with 0.1, 0.5, 1.0, 2.0 and 5.0% of Tm-doping concentration. After the phase confirmation by powder XRD, photoluminescence (PL) and scintillation properties were systematically measured, including PL emission map, PL decay time, scintillation spectra, scintillation decay time and pulse height spectra. When we irradiated X-rays, we observed the scintillation emission at 360 and 460 nm caused by Tm3+ 4f-4f transitions. Under 662 keV γ-ray irradiation, we determined absolute scintillation light yield of 2340 ph/MeV for the 2.0% Tm doped sample. Taking into account whole optical and scintillation properties, 2.0% doping was the best for Tm-doped LPS crystals. • We successfully synthesized LPS single crystals with Tm doping concentration of 0.1 to 5.0 % by the FZ method. • When we irradiated X-rays, we observed the scintillation emission at 360 and 460 nm caused by Tm3+ 4f-4f transitions. • Under 662 keV γ-ray, scintillation light yield of Tm doped LPS reached up to 2340 ph/MeV with the 2.0 % Tm doped sample. • The optimal Tm doping concentration in the LPS single crystal for a scintillator was determined to be around 2.0 %. [ABSTRACT FROM AUTHOR]

• BaSiO 3 :Ce crystals are developed using the floating zone method. • Under 137Cs γ-ray irradiation, the 1.0 % Ce-doped sample shows a photoabsorption peak. • A complementary relationship between scintillation and storage luminescence properties is observed. We developed BaSiO 3 :Ce crystals with different Ce concentration of 0.5, 1.0 and 2.0 % using the floating zone method, and evaluated the PL, scintillation and ionizing radiation induced storage luminescence properties. Under X-ray irradiation, a broad emission band appears at around 400 nm due to 5d–4f transitions of Ce3+. The decay time constants are in a range of 43–47 ns, which is a typical time constant of 5d-4f transitions of Ce3+. Under 137Cs γ-ray irradiation, only the 1.0 % Ce-doped sample shows a photoabsorption peak, and the scintillation light yield is ∼1500 ph/MeV. The results of pulse height spectra and TSL glow curves demonstrates a complementary relationship between scintillation and ionizing radiation induced storage luminescence properties in this material. [ABSTRACT FROM AUTHOR]

Pr doped Lutetium pyrosilicate Lu 2 Si 2 O 7 (LPS) single crystals were synthesized by the floating zone method with different Pr concentration from 0.1% to 2.0%. After the confirmation of the phase by powder XRD patterns, optical and scintillation properties were investigated. When we observed photoluminescence (PL) emission spectra, emission due to 5d-4f transition of Pr3+ appeared in all the samples at wavelength of 300–340 nm, and PL decay times were similar around 9–11 ns in all the samples. In scintillation properties, under the X-ray excitation, all the samples had the same scintillation emission spectral shape with different emission intensities, and scintillation decay times were around 18–21 ns. Under 137Cs γ-rays irradiation, the 1.0% Pr doped sample showed the highest scintillation light yield among the present samples, and the value was 9700 ph/MeV. Furthermore, linearity as a function of γ-ray energy was observed. • We successfully synthesized LPS single crystals with Pr doping concentration of 0.1, 0.3, 0.5, 1, and 2 % by the FZ method. • All of the samples have scintillation decay time around 18–21 ns. • When excited by 662 keV γ-ray, 1.0 % Pr doped LPS have scintillation light yield up to 9700 ph/MeV. • The optimal Pr doping concentration in the LPS single crystal for the scintillation purpose was determined to be around 1 %. [ABSTRACT FROM AUTHOR]

(Eu x ,Y 1- x) 3 Al 5 O 12 (x = 0.005, 0.01, 0.05, 0.10, 0.15, and 0.20) single crystals were prepared by the floating-zone method. We investigated their photoluminescence (PL) and scintillation properties including PL excitation/emission contour spectra, PL quantum yields, PL decay times, X-ray-induced scintillation spectra, scintillation decay times, and pulse-height spectra under γ-ray irradiation from 137Cs (662 keV). The PL and scintillation spectra exhibited some emission lines at visible wavelength due to the 4f-4f transitions of Eu3+ ions, and the PL and scintillation decay times resulted several milliseconds. Among all the samples, (Eu 0.1 ,Y 0.9) 3 Al 5 O 12 and (Eu 0.15 ,Y 0.85) 3 Al 5 O 12 single crystals showed the highest PL quantum yield. On the other hand, (Eu 0.01 ,Y 0.99) 3 Al 5 O 12 single crystal showed the highest light yield. The light yield of the sample was estimated to be 36,000 photons/MeV from the pulse height spectrum. • Eu-doped YAG single crystals were grown by the floating zone method. • Scintillation properties of Eu-doped YAG were investigated. • Emission peaks due to 4f-4f transitions of Eu3+ ions were observed. • 1.0 % Eu-doped YAG showed the highest light yield (36,000 photons/MeV). [ABSTRACT FROM AUTHOR]