[en] Single crystalline films (SCF) of Lu₂SiO₅ (LSO) and Lu₂SiO₅:Ce (LSO:Ce) silicates with thickness of 2.5-21 μm were crystallised by liquid phase epitaxy method onto undoped LSO substrates from melt-solution based on PbO-B₂O₃ flux. The luminescence and scintillation properties of LSO and LSO:Ce SCFs were compared with the properties of a reference LSO:Ce and LYSO:Ce crystals. The light yield (LY) of LSO and LSO:Ce SCF reaches up 30 % and 145 %, respectively, of that of a reference LSO:Ce crystal under excitation by α-particles of ²⁴¹Am source (5.5 MeV). We found that the luminescence spectrum of LSO:Ce SCF is red-shifted with respect to the spectrum of a reference LSO:Ce crystal. Differences in luminescence properties of LSO:Ce SCF and single crystal are explained by the different distribution of Ce³⁺ over the Lu1 and Lu2 positions of LSO host and are also due to Pb²⁺ contamination in the former.

[en] We provide a systematic comparison of the scintillation and luminescence properties, including emission mechanisms, of the highly efficient cerium-doped scintillators lutetium-(gadolinium) orthosilicates Lu₂(SiO₄)O (LSO), (Lu_1−xGd_x)₂(SiO)₄O(LGSO) and Gd₂(SiO₄)O (GSO). Determined characteristics manifest an advantage of LGSO:Ce with respect to both LSO:Ce and GSO:Ce for scintillator applications around room temperature. This is thanks to combined fast decay (faster than both limit compositions) high light yield, similar to that of LSO:Ce (twice higher than GSO:Ce) and low afterglow, similar to that of GSO:Ce (almost two orders of magnitude lower than LSO:Ce). High temperature applications do not, however, seem to be a suitable option for LGSO:Ce due to evidenced thermal ionization of both Ce1 and Ce2 centres above room temperature. (paper)

[en] The work is focused on the development of production methods of large scintillators based on lutetium-gadolinium oxyorthosilicate doped with cerium Lu_2xGd_2−2xSiO₅:Ce (LGSO:Ce). Large LGSO:Ce crystals were grown by the Czochralski method, and a set of experimental samples for testing of scintillation characteristics was produced. Possibilities are discussed to use this scintillator in high energy physics experiments. In particular, an electromagnetic calorimeter to search for conversion of electrons into muons, which is forbidden in the Standard Model. -- Highlights: • We report comparative tests of scintillation characteristics of LGSO:Ce, LSO:Ce, and LYSO:Ce crystals. • Large crackless LGSO:Ce crystals are grown by the Czochralski method. • Possibility to use this scintillator in electromagnetic calorimeter for search of electron conversion into muons is studied. • LGSO:Ce energy resolution at 662 keV is by 1.3–2.2% better compared to LSO:Ce and LYSO:Ce

[en] This work focuses on the study of changes in the optical transmission of Y_2SiO_5:Ce crystals caused by ionizing radiation from γ-quanta and high energy protons. Radioisotope content of proton-irradiated crystals, transmission and induced absorption spectra, and scintillation characteristics are measured after irradiation with protons. In contrast to crystals of heavy complex oxides, Y_2SiO_5:Ce crystals do not demonstrate significant deterioration of transmission in the luminescence range (400–600 nm) under irradiation. Such crystals can be considered as a material for construction of detecting cells of the calorimetric detectors at LHC with high luminosity. The feasibility of growing large crackless Y_2SiO_5:Ce crystals with a diameter up to 50 mm and length up to 250 mm is demonstrated. - Highlights: • Large YSO:Ce single crystals are obtained. • YSO:Ce demonstrates improved radiation hardness compared to heavy scintillators. • YSO:Ce is a promising crystal for LHC detectors upgrade

[en] Single crystals of Lu_2xGd_2-2xSiO₅: Ce (0 < x < 1) compounds with different atomic ratios Lu/(Lu + Gd) have been grown by the Czochralski method. It has been shown that a change in the spatial symmetry from P2₁/c to C2/c in the course of substitution of lutetium for gadolinium occurs at the ratio Lu/(Lu + Gd) = 0.1. The lattice thus formed with symmetry C2/c in the structure of Lu_2xGd_2-2xSiO₅: Ce crystals favors the maximum possible incorporation of Ce³⁺ ions into the sevenfold-coordinated position with respect to oxygen. This explains the substantial improvement of the scintillation characteristics of the grown crystals.