Search

All‐inorganic halide perovskites appear as a promising class of scintillators for radiation detection applications due to their excellent optoelectronic properties. Herein, a self‐activated perovskite CsEuBr3 single crystal is developed as an efficient X‐ and γ‐ray scintillator. Single crystals of CsEuBr3 are grown by the Bridgman method. The phase structure, stability, photophysics properties, and scintillation performance of CsEuBr3 single crystals are studied. Under X‐ray irradiation, its emission peaks at 445 and 510 nm, associated with Eu2+ 5d–4f and defect‐related emission, respectively, are studied. Under 137Cs gamma irradiation, it has a decent light yield of 22 000 ± 2000 photons MeV−1 and an energy resolution of 6.2 ± 0.4% at 662 keV with a scintillation decay of 510 ns. [ABSTRACT FROM AUTHOR]

NaI:Tl,6Li bulk crystals are regarded as promising neutron-gamma (n-γ) scintillators because of low production cost and superior n-γ pulse shape discrimination (PSD) performance. In this work, some rare earth elements (Gd, Y, Lu and Sc) co-doped NaI:Tl,6Li single crystals were grown by the multi-ampoule Bridgman method. It was found that the rare earth co-doping significantly improves the pulse height discrimination (PHD) capability of NaI:Tl,6Li with high alpha/beta (α/β) ratio, approaching to 100%. The optimal α/β ratios achieved for Gd, Y, Lu and Sc co-doped NaI:Tl,6Li are 0.85, 0.93, 0.95, and 0.83, respectively. Electron equivalent energy per neutron interaction is above 3.96 MeV and can be as high as 4.54 MeV, close to the Q value of 4.78 MeV for 6Li(n, α)3H interaction. Moreover, the rare earth co-doped NaI:Tl,6Li crystals still maintain the superior PSD capability with figure of merit (FoM) in the range of 2.1–3.3. These results highlight the great potential of rare-earth co-doped NaI:Tl,6Li crystals serving as high-performance n-γ scintillators. [ABSTRACT FROM AUTHOR]

Inorganic phosphors based on rare earth elements are commonly used as scintillation materials due to their high chemical and radiation resistance. In this work, we study gadolinium oxyselenide as a new phosphor material. The work describes a facile synthesis method for Gd 2 O 2 Se. Single crystal structure of this compound was determined for the first time: sp.gr. P ¯3 m 1 with a ​= ​3.8911(4) Å and c ​= ​6.8829(8) Å. Gd 2 O 2 Se is stable in the inert atmosphere and melts at 2075 ​± ​20 ​°C. This material is also stable when heated in air up to 720 ​°C. with the following oxidation and weight increase. This mass increase can be explained by the oxidation of Se2− to Se4+. Further temperature increase above 952°С leads to a sharp mass loss and the final mass of sample corresponds to full oxidation of Gd 2 O 2 Se to gadolinium oxide. The band gap of the material was estimated to be 3.6 ​eV. Photoluminescence spectrum for Gd 2 O 2 Se:Tb3+ shows the characteristic transitions in Tb3+ ion with the most intense green emission that corresponds 5D 4 → 7F J transitions. [Display omitted] • A powder of Gd 2 O 2 Se was obtained and the single crystal structure was determined: sp.gr. P ¯3 m 1, a ​= ​3.89Å, c ​= ​6.88 Å. • The melting point was found to be 2075 ​± ​20 ​°C. High air stability for this compound was demonstrated up to 720 ​°C. • The estimated value of the band gap is 3.6 ​eV. The photoluminescence of the Tb3+ doped sample was investigated. [ABSTRACT FROM AUTHOR]

The Li 6 Y(BO 3) 3 :Pr3+, an alkali orthoborate compound have been synthesized as polycrystalline powders with different doping concentration of Pr3+ rare-earth as an activator. The transparent single crystal has also been grown in argon atmosphere by the Czochralski method with 1 mol. % of Pr3+ doping element. The grown crystal possesses a monoclinic structure with a space group of P 2 1 / c. The crystal has been cut and optically polished to study the luminescence properties with X-ray, UV, α-particles, and γ-ray excitations. The crystal has showed relaxed 4f15d-4f2 emission at 309 nm along with characteristic 4f2-4f2 transition emissions. The UV–Vis–NIR absorbance spectrum has been obtained in the range of 250–2000 nm. Above 300 nm the crystal has showed about 50% transmittance. The Commission International De I'Eclairage (CIE) chromaticity diagram is depicting the change in combined emission colors for different excitation positions. The scintillation properties of the crystal have been studied with γ-ray from 60Co, α-particles from 241Am and moderated thermal neutrons from a252Cf source. The pulse shape discrimination, obtained for γ-ray, α-particles, and moderated thermal neutrons has shown the potential of this scintillator for thermal neutron detection. • 1 mol% Pr3+ doped Li 6 Y(BO 3) 3 single crystal has been grown using Czochralski method. • 4f15d-4f2 transition luminescence has been observed in UV–Vis measurements. • UV–Vis–NIR absorbance has been studied for 3H 6 to 3P 2 , 3P 1 /1I 6 , 3P 0 , 1D 2 , 1G 4 , 3F 4 , 3F 3, and 3F 2 transitions. • CIE chromaticity 1931 diagram has been plotted for different UV excitations. • A good discrimination of thermal neutrons to γ-rays has been observed with pulse shape discrimination method. [ABSTRACT FROM AUTHOR]