Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 4

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Recombination Processes in PbWO_{4}:Tb^{3+} Crystals

100%
Novosad S., Kostyk L., Novosad I., Tsvetkova O.
|
|
issue 1
143-145
EN
In the paper the results of investigations of X-ray excitation spectra, thermostimulated luminescence and the influence of light illumination on the thermoluminescence glow curves of pure and Tb-doped PbWO_{4} crystals are presented. It is suggested that the F^{-}-centres are formed in PbWO_{4} crystals at filling oxygen vacancies near Pb^{3+} ions to three electrons under X-ray irradiation at 90 K. The nature of 108 K thermostimulated luminescence peak is connected with the [(WO_{3} + F^{-})-Pb^{3+}] associations. It was established that thermal or optical destruction of this peak leads to appearance of the radiative transitions of excitons localized near the [(WO_{3} + F)-Pb^{2+}] complex centres.
2
Content available remote

Origin of Point Defects in β-Ga₂O₃ Single Crystals Doped with Mg²⁺ Ions

100%
Luchechko A., Vasyltsiv V., Kostyk L., Tsvetkova O.
Acta Physica Polonica A
|
2018
|
vol. 133
|
issue 4
811-815
EN
Optical absorption and photoconductivity investigations of nominal pure and Mg²⁺ doped β-Ga₂O₃ single crystals have been carried out. Additional bands in the UV (3.6-4.6 eV) and near-IR (0.4-1.2 eV) spectral regions were found in optical absorption and photoconductivity spectra. A correlation between Mg²⁺ doping, annealing in oxygen atmosphere as well as optical absorption and photoconductivity bands were established in gallium oxide. Electronic transitions from shallow traps and F-centers were observed in the IR spectral region (0.4-1.2 eV). Absorption and photoconductivity in the UV region are related to deep acceptor levels created by native defects and impurities.
3
Content available remote

Luminescence and Luminescence Kinetics of Gd_{3}Ga_{5}O_{12} Polycrystals Doped with Cr^{3+} and Pr^{3+}

88%
Mahlik S., Kukliński B., Grinberg M., Kostyk Ł., Tsvetkova O.
|
|
issue 1
117-121
EN
In this paper spectroscopic investigations of Gd_3Ga_5O_{12} (GGG) polycrystals, containing Cr^{3+} and intentionally doped with Pr^{3+} of concentrations 0.5, 1 and 1.5 mol% are presented. We have measured the steady state luminescence and luminescence excitation spectra, as well as the time resolved spectra and luminescence kinetics. The main goal was to investigate the excitation energy transfer from lattice to impurity and between impurities. We found that relative intensity of Cr^{3+} and GGG lattice luminescence decreased when material was doped with Pr^{3+}. On the other hand, time resolved spectroscopy and luminescence decay measurements showed that the Cr^{3+} and GGG lattice luminescence decays were independent of Pr^{3+} content. The lifetime of Pr^{3+} luminescence related to ^{1}D_{2} → ^{3}H_{4} and ^{3}P_{0} → ^{3}H_{4} transitions decreased with concentration of Pr^{3+}, which was attributed to the concentration luminescence quenching. No energy transfer between GGG lattice defects and Cr^{3+}, and Pr^{3+} ions was observed. We proposed the model of radiative recombination of electron and hole, which took place through three independent pathways: by GGG host emission that peaked at 12750 cm^{-1}, by Cr^{3+} luminescence that peaked at 15400 cm^{-1}, and by Pr^{3+} luminescence.
4
Content available remote

Recombination Luminescence in Ca_{3-x}Cd_xGa₂Ge₃O₁₂ Garnets Doped with Eu³⁺ Ions

76%
Kostyk L., Luchechko A., Novosad S., Panasyuk M., Rudko M., Tsvetkova O.
Acta Physica Polonica A
|
2018
|
vol. 133
|
issue 4
943-947
EN
The results of the investigations of X-ray excitation spectra, thermostimulated luminescence and influence of light illumination on the thermoluminescence glow curves of Eu³⁺-doped Ca_{3-x}Cd_xGa₂Ge₃O₁₂ garnet polycrystalline samples are presented. It is shown that Ca_{3-x}Cd_xGa₂Ge₃O₁₂ polycrystalline samples are characterized by intrinsic luminescence, which consists of several components. The nature of intrinsic luminescence is discussed. It is suggested that the nature of thermoluminescence glow peak near 150 K is connected with the [(V_{Ge}+V_{O})¯-F⁺] associations formed under X-ray irradiation at 85 K. The influence of light illumination on the TSL intensity of the preliminary X-ray irradiated samples is shown.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.