The steady-state and time-resolved emission and excitation spectra and luminescence decay kinetics of nominally undoped Lu sub(2)SiO sub(5) single crystalline films (SCFs) grown by the liquid phase ...epitaxy method from the PbO-based flux are studied in the range 4.2-300 K. Due to the preparation method, the films contain lead ions. Luminescence characteristics of Pb-related centres of different types are identified. A weak 3.65 eV emission is ascribed to the radiative decay of the triplet relaxed excited state (RES) of Pb super(2+) ions substituting for Lu super(3+) ions in the Lul lattice sites of the X sub(2) structure. Possible origins of the intense complex lead-related approximately 2.8eV emission are discussed. We propose phenomenological models describing the excited-state dynamics of the studied luminescence centres. We also determine the characteristic parameters of the corresponding RESs, in particular, the energy separations between the excited states and the rates of the radiative and non-radiative transitions from these states.
The absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300 K for the double Bi3+aCe3+-doped and separately Bi3+- and Ce3+-doped ...Y3Al5O12 (YAG) and Lu3Al5O12 (LuAG) single crystalline film phosphors grown by liquid phase epitaxy method. Emission bands in the UV range arising from the intrinsic radiative transitions of Bi3+-based centers, and emission bands in the visible range related to the luminescence of excitons localized around Bi-based centers, were identified in both BiaCe and Bi-doped YAG and LuAG SCF. Energy transfers from the host lattice to Bi3+ and Ce3+ ions and from Bi3+ to Ce3+ ions were investigated. Competition between Bi3+ and Ce3+ ions in the energy transfer from the YAG and LuAG hosts was evidenced. A strong decrease of intensity of the Ce3+ luminescence both in YAG:Ce and LuAG:Ce SCF phosphors, grown from a Bi2O3 flux, is observed due to the quenching influence of Bi3+ flux related impurity. Due to overlap of the visible emission band of Bi3+ centers with the absorption band of Ce3+ ions peaking at around 450a460 nm, an effective energy transfer from Bi3+ ions to Ce3+ ions takes place, resulting in the appearance of a slower component in the Ce3+ luminescence decay kinetics.
The work is dedicated to the development of scintillating screens based on single crystalline films (SCF) of Ce doped Lu-Y-Al perovskites grown by the liquid phase epitaxy method. We show in this ...work that Lu sub(1-x)Y sub(x)AP:Ce SCF with very good structural and optical perfection can be grown from the PbO-based flux onto YAP substrates in all range of x-values. We also found the Lu sub(1-x)Y sub(x)AP:Ce SCF can be crystallized by LPE method from the lead free BaO-B sub(2)O sub(3)-BaF sub(2) flux onto YAP substrates in the range of x values up to 0.4 formula units.
The luminescence of CaWO4:Bi single crystals ZORENKO, Yu; PASHKOVSKY, M; VOLOSHINOVSKII, A ...
Journal of luminescence,
2006, 2006-1-00, Letnik:
116, Številka:
1-2
Journal Article
The article presents a case of a surgical treatment of removing a dermoid cyst of the floor of the oral cavity in a patient with severe hemophilia A. A detailed analysis was carried out of the ...surgical operation, postoperative management, coagulation factor replacement therapy and accompanying therapy, as well as the features of anesthesia, which allowed a surgical intervention without any hemorrhagic and infectious complications.
Luminescence of the Bi super(3+) single and dimer centers in UV and visible ranges is studied in YAG:Bi (0.13 and 0.27 at% of Bi, respectively) single crystalline films (SCFs), grown by liquid phase ...epitaxy from a Bi sub(2)O sub(3) flux. The cathodoluminescence spectra, photoluminescence decays, and time-resolved spectra are measured under the excitation by accelerated electrons and synchrotron radiation with energies of 3.7 and 12 eV, respectively. The energy level structure of the Bi super(3+) single and dimer centers was determined. The UV luminescence of YAG:Bi SCF in the bands that peaked at 4.045 and 3.995 eV at 300 K is caused by radiative transitions of Bi super(3+) single and dimer centers, respectively. The excitation spectra of UV luminescence of Bi super(3+) single and dimer centers consist of two dominant bands, peaked at 4.7/4.315 and 5.7/6.15 eV, related to the super(1)S sub(0)--> super(3)P sub(1) (A band) and super(1)S sub(0)--> super(1)P sub(1) (C-band) transitions of Bi super(3+) ions, respectively. The excitation bands that peaked at 7.0 and 7.09 eV are ascribed to excitons bound with the Bi super(3+) single and dimer centers, respectively. The visible luminescence of YAG:Bi SCF presents superposition of several wide emission bands peaking within the 3.125-2.57 eV range and is ascribed to different types of excitons localized around the Bi super(3+) single and dimer centers. Apart from the above mentioned A and C bands the excitation spectra of visible luminescence contain wide bands at 5.25, 5.93, and 6.85 eV ascribed to the O super(2-)-->Bi super(3+) and Bi super(3+)-->Bi super(4+) + e charge transfer transition (CTT) in Bi super(3+) single and dimer centers. The observed significant differences in the decay kinetics of visible luminescence under excitation in A and C bands of Bi super(3+) ions, CTT bands, and in the exciton and interband transitions confirm the radiative decay of different types of excitons localized around Bi super(3+) ions in the single and dimer centers.
This research is directed on creating by liquid phase epitaxy the single crystalline film scintillators based on undoped and Bi doped CdWO 4 compounds as well as the phoswich detector based on "CdWO ...4 :Bi or CdWO 4 films/CdWO 4 or CdWO 4 :Bi crystals" epitaxial structures. The luminescent and scintillation properties of the undoped and Bi 3+ doped (in a concentration range of 0.04-0.25 at. %) CdWO 4 films, grown by LPE method from Na 2 WO 4 flux, were compared with the properties of CdWO 4 bulk crystal analogs, grown from melts by the Czochralski method. Using the traditional luminescence spectroscopy and the luminescence spectroscopy under excitation by pulsed synchrotron radiation with energy in the fundamental absorption range of CdWO 4 host, we have also examined the nature of different emission centers and studied energy transfer processes from tungstate hosts to Bi 3+ ions and defect centers in CdWO 4 and CdWO 4 :Bi films and their crystal analogs.
Methodological recommendations for surgical care in patients with hemophilia A receiving prophylactic therapy with emicizumab. Recommendations of the expert group. Moscow, 2024.
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