Results 241 to 250 of about 69,993 (291)

Secondary photorefractive centers in Sn_2P_2S_6:Sb crystals

Optics Letters, 2011
Secondary photorefractive centers in Sb-doped Sn2P2S6 have a lifetime comparable to the formation time of the space-charge grating. This considerably affects the dynamics of two-beam coupling and results in a new type of transient gain enhancement for preilluminated samples.
Dean R, Evans, Alexandr, Shuymelyuk, Gary, Cook, Serguey, Odoulov   +3 more
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The boron center: A new luminescent center in ZnS crystals

Journal of Luminescence, 1979
Abstract In ZnS crystals containing B, insensitivity of the emission to high pressure, the structure of the excitation spectra and the observed absence of the photo-excited EPR signals suggest that the luminescence may be due to a localized transition between closely associated B Zn and V Zn .
P. Jaszczyn-Kopec, H.D. Fair, D.S. Downs
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F-Centers in BaBrI Single Crystal

IEEE Transactions on Nuclear Science, 2020
In this article, we demonstrate the results of experimental and theoretical studies of F-centers in BaBrI single crystals. We have observed two types of F-centers related to an electron trapped in the iodine or bromine vacancy site. It was found that absorption bands due to F-centers can be induced either by radiation or additive coloration.
Roman Shendrik, Nikolay Popov, Alexandra Myasnikova   +2 more
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Colored Centers in Ionic Crystals

2000
When a vacancy is created in a crystal, an electron may be trapped at this location. This bound electron can absorb light at well defined frequencies, thus changing the color of the crystal.
Jean-Louis Basdevant, Jean Dalibard
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Trapping center parameters in In6S7 crystals

Physica B: Condensed Matter, 2011
Abstract Thermally stimulated current measurements were carried out on In 6 S 7 single crystals in the temperature range of 10–225 K with a constant heating rate of 0.8 K/s. The study of trapping centers was accomplished by the measurements of current flowing along the c -axis of crystals. The analysis of the glow curve according to various methods,
M. Isik, N.M. Gasanly
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Transient color centers in GGG crystals

Radiation Effects and Defects in Solids, 2002
Electron pulse induced absorption and their decay kinetics have been investigated in samples of GGG crystals with different starting absorption spectra. It is shown that for all samples there appears a wide transient absorption (TA) band with two maxima in the region 14,000-17,000 v cm m 1 and 22,000-26,000 v cm m 1 .
P. Potera, A. Matkovskii, D. Sugak, L. Grigorjeva, D. Millers, V. Pankratov   +5 more
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Molybdenyl centers in NH4Cl single crystals

The Journal of Chemical Physics, 1977
Molybdenyl centers are studied in single crystals of NH4Cl using a set of correlated experimental techniques like EPR, optical absorption, infrared absorption, conductivity, and dielectric loss. EPR studies on NH4Cl single crystals doped with (MoOCl5)2− are made over a wide temperature range. At room temperature the resonance due to even isotopes of Mo
S. Radhakrishna, B. V. R. Chowdari, A. Kasi Viswanath   +2 more
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Luminescence Centers in Crystals

1976
Investigation of the Spectral-Luminescence Properties of Ruby as Active Laser Medium.- I. Spectral Distribution of Luminescence Quantum Efficiency and Absorption Spectra.- II. Phosphorescence of Ruby. Energy Band Scheme.- III. Color Centers in Ruby.- IV.
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Crystal Field at the Impurity Center Sites in Ionic Crystals

Physics of the Solid State, 2005
Perturbation theory is developed for second-quantized operators in a basis of partly nonorthogonal orbitals. This method may be helpful in carrying out ab initio calculations of the parameters of the crystal field at the impurity center sites. As an illustration, when estimating the crystal field parameters for Yb3+: KZnF3, some fitting parameters are ...
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New Color Centers in KCl Crystals

physica status solidi (b), 1973
AbstractNew absorption centers giving bands with maxima at 555 nm (Y) and 625 nm (Y′) at liquid‐nitrogen temperature, were observed in OH–containing KCl single crystals annealed in vacuum a t 600 °C and subsequently uv irradiated. The thermal bleaching of these bands yields F centers.
G. Matsumura, G. C. Kuczynski
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