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Gadolinium pyrosilicate (GPS, Gd2Si2O7) single crystals with different doping concentrations of Tb (0.1–2.0 mol%) are successfully fabricated using the floating-zone technique. In this work, the dependence of Tb-doping concentration on the photoluminescence (PL) and scintillation properties of Tb-doped GPS (Tb:GPS) has been investigated. The PL emission contour graph shows multiple emissions, with the strongest emissions at 378 nm for 0.1% and 0.5% Tb-doping and 544 nm for 1.0% and 2.0% Tb-doping, corresponding to Tb3+ 4f-4f transitions. The PL lifetimes of the specimens range from 4.89 to 5.22 ms. The scintillation spectra exhibit comparable wavelength and intensity trends to the PL emission. The scintillation lifetimes of the specimens range from 2.41 to 3.88 ms. The Tb:GPS specimens demonstrate a relatively excessive afterglow level, with Af20 values ranging from 1640 to 7250 ppm and Af40 values ranging from 136 to 362 ppm. Using recently developed pulse height measurement for millisecond decay scintillators, under excitation at 662 keV γ-rays, the 1.0% Tb:GPS specimen exhibits the highest scintillation light yield among all other specimens at 95,600 ph/MeV, making Tb:GPS one of the highest light yield oxide scintillators. [ABSTRACT FROM AUTHOR]

Series of 1.0% Terbium (Tb)-doped rare-earth pyrosilicate single crystals including Lu2Si2O7 (LPS), Y2Si2O7 (YPS), Gd2Si2O7 (GPS), and La2Si2O7 (LaPS) have been prepared by the floating-zone method. After the phase confirmation by powder X-ray diffraction, the properties are measured on both photoluminescence and scintillation aspects, including the photoluminescence emission contour graph and decay times, X-ray induced scintillation spectra and decay times, afterglow profiles, and the recently developed pulse height spectra for scintillators with millisecond decay time. The results indicate the multiple emissions from Tb3+ 4f-4f transition with the dominant emission at 540 nm (5D4 → 7F5) on both ultraviolet and X-ray excitation with the decay time around 2.6–5.6 and 1.3–3.2 ms, respectively. Under the γ-ray irradiation from 137Cs, the Tb-doped LPS, YPS, GPS, and LaPS have presented scintillation light yields of 20,700, 29,600, 95,600, and 47,700 ph/MeV with ±10%, respectively, which considerably very high among the oxide scintillators. [ABSTRACT FROM AUTHOR]

Five samples of lanthanum pyrosilicate (La2Si2O7) single crystals with 0.5–10.0% Praseodymium (Pr)-doping concentrations were synthesized by the floating-zone method. Photoluminescence and scintillation properties of these crystals were investigated in this study for the first time. The multiple emissions from electron transitions of Pr3+ were observed on both a photoluminescence emission map and scintillation spectra, including the desired emission band of Pr3+ 5d–4f transition at 250–310 nm. The major photoluminescence and scintillation decay times were approximately 19 and 26 ns, respectively. When compared with commercial scintillators such as Tl-doped cesium iodide (CsI), the Pr-doped La2Si2O7 samples presented a respectively low afterglow level of 32 ppm after 20 ms of X-ray irradiation. Under 662 keV γ-ray irradiation from 137Cs, the 3.0% Pr-doped La2Si2O7 sample presented a scintillation light yield of 3200 ph/MeV, which was the best value among the tested samples. [ABSTRACT FROM AUTHOR]

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-gadolinium pyrosilicate ((Y 2-x Gd x)Si 2 O 7) single crystals with different ratios of yttrium to gadolinium (x = 0.1–1.9) and 2% Ce-dopant were successfully synthesized using the floating-zone method. In this work, photoluminescence (PL) and scintillation properties of 2% Ce-doped (Y 2-x Gd x)Si 2 O 7 were investigated. The conducted experiments included PL decay time and emission, X-ray-induced decay time and scintillation spectra, an afterglow analysis, as well as the total scintillation light yield by γ-ray-irradiation pulse-height spectra. Interesting results were including the considerably low afterglow at 20 ms of 40–65 ppm compared to commercial scintillator materials on the market like CdWO 4. Further, the high light yield of 21,800 ph/MeV was achieved in Y 0.5 Gd 1.5 Si 2 O 7 under 662 keV (137Cs) γ-ray-irradiation. • 2% Ce-doped Yttrium-gadolinium pyrosilicate ((Y 2-x Gd x)Si 2 O 7 , x = 0.1–1.9) with were crystal growth by FZ-method. • PL and scintillation spectrum show emission at 350-420 nm From the Ce3+ 5d-4f transitions with The PL QY up to 73.1%. • PL and scintillation decay time constant result in 25–29 and 28–32 ns, respectively. • The samples afterglow level at 20 ms (Af 20) are 40–65 ppm. • Under 662 keV γ-ray, scintillation light yield of Ce doped YGPS is up to 21,800 ph/MeV for the Y 0.5 Gd 1.5 Si 2 O 7 sample. [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]

Oxyfluoride‐based sodium‐aluminum‐phosphate glasses with a fixed 7 mol% content of Gd2O3 and various amounts of CeF3 were fabricated by the melt quenching process. The fabricated glasses (NAPGCe) were studied by physical, optical, scintillation, and light yield properties. In NAPGCe glasses, intense emission peaks were observed at 312 nm (6P7/2 → 8S7/2) for Gd3+ and 336 nm (5d → 4f) for Ce3+ ions in both photoluminescence (275 and 294 nm) and radioluminescence (X‐ray) spectra. Upon excitation with 275 nm ultraviolet radiation, a decrease in Gd3+ emission and an increase in Ce3+ emission intensity lead to efficient energy transfer (ET) from Gd3+ to Ce3+ ion in NAPGCe glasses. The bi‐exponential function was applied to fit the non‐exponential decay curves of NAPGCe glasses and then calculated their lifetimes in the order of fast (18.25–16.94 ns) and slow (72.99–67.74 ns) decay times. An overall integrated scintillation efficiency of about 67% was estimated for NAPGCe0.10 glass compared to bismuth germanate oxide (BGO:Bi4Ge3O12) crystal. Under 241Am α‐ray (5.5 MeV) source, the light yield of the NAPGCe1.00 glass was obtained by comparing it with a commercial Li‐glass scintillator (GS20), and it was found to be 26 photons MeV−1. [ABSTRACT FROM AUTHOR]

• LPS single crystals with Nd doping concentration of 0.1%, 0.5%, 1.0%, 2.0%, and 5.0% were synthesized by the FZ method. • Under X-ray irradiated, Sample exhibited scintillation emission at both UV and NIR ranged caused by Nd3+ 4–4f transitions. • X-ray induced scintillation decay time of Nd-doped LPS samples resulted in 3–4 μs. • Under 662 keV γ-ray, scintillation light yield of Nd-doped LPS reached up to 800 ph/MeV in the 2.0% Nd-doped sample. Lutetium pyrosilicate (Lu 2 Si 2 O 7 , LPS) single crystals were synthesized by the floating-zone method with different dopant concentration to investigate the Nd-concentration dependence on the photoluminescence (PL) and scintillation properties. The Nd-doped LPS presented PL peaking at 800–900 nm due to the 4–4f transitions with the PL quantum yield up to 34%. Under X-ray irradiation, the samples showed several sharp peaks in both UV–visible and NIR regions. The scintillation decay time constants were around 3–4 μs upon pulsed X-ray excitation, and the afterglow level at 20 ms after X-ray irradiation was 310–650 ppm. The scintillation light yields of the Nd-doped LPS under γ-rays from 137Cs were up to 800 ph/MeV. hMeV. [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]

0.1, 0.3, 0.5, 1.0, 5.0, and 10.0 % Sm3+-doped Y 3 Al 5 O 12 single crystals were grown by the floating zone method. Photoluminescence (PL) and radioluminescence (RL) properties of the samples were evaluated and the emission peaks due to 4f-4f transitions of Sm3+ ions were observed. The PL quantum yield of the 0.3 % Sm3+-doped sample was highest among all the samples (approximately 48 %). PL and RL decay times of the samples were 0.7–2.7 and 0.6–2.9 ms, respectively. The light yield of the 0.5 % Sm3+-doped sample under γ-ray excitation was highest and its value was estimated to be approximately 8400 photons/MeV using a measurement system for scintillators with slow decay times. [ABSTRACT FROM AUTHOR]