Results 261 to 270 of about 20,279 (296)

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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Aggregation of impurity centers in ionic crystals

Russian Physics Journal, 2007
Results of modeling of the aggregation process in complex centers of ionic crystals are presented. Concentration dependences of the number of paired centers are obtained. A nature of the paired luminescence centers is discussed.
M. K. Myrzahmet, K. S. Baktybekov
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Trapping centers in inse single crystals

Materials Chemistry and Physics, 1983
Abstract A systematic investigation of centers acting in InSe single crystals has been carried out by means of the following electric and photoelectronic techniques: 1. a) Resistivity behaviour as a function of temperature, analyzed by the single donor-single acceptor model 2.
M. Di Giulio, G. Micocci, L. Ruggiero, A. Tepore, F. Zuanni   +4 more
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Lattice Vibrations in Crystals with Molecular Impurity Centers

Physical Review, 1963
The Green's function formalism of Lifshitz and others for the calculation of lattice vibrations in impure crystals is restricted to disturbed lattices with an unchanged number of particles (monatomic impurity centers). A method is given here which reduces the problem of polyatomic impurities to the Lifshitz formalism.
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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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Color centers in lead molybdate crystals

Physics of the Solid State, 2003
Color center formation in PbMoO4 crystals, originating from nonstoichiometric batch composition, BaO and Bi2O3 additions, high-temperature annealing of crystals, and UV illumination, is discussed. Additional optical absorption bands are identified. The photochromism of the crystals is shown to be due to charge exchange, Pb2+ + Mo6+ ⇄ Pb3+ + Mo5+, of ...
T. M. Bochkova, M. D. Volnyanskii, D. M. Volnyanskii, V. S. Shchetinkin   +3 more
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Lithium–(F_2^+)A centers in alkali-halide crystals

Optics Letters, 1981
New absorption and emission bands are reported for KBr, KI, and RbI that are attributed to the lithium-(F(2)(+))(A) center.
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Colour centers in synthetic fluorite crystals

Physica, 1958
Synopsis A study of the coloration of fluorite crystals after irradiation and additive coloration has been made. Bleaching experiments and lattice parameter measurement lead us to probable models for the α and β centers. The β center should be a normal F-center, the α center an F-center coupled to an interstitial fluorine ion.
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Controlled crystallization of BaO–B2O3–Bi2O3 Glass in the temperature range of a supercooled melt in the presence of additional nucleation centers

Journal of Non-Crystalline Solids, 2022
A M Kut'In, V S Shiryaev
exaly  

On A-centers in Colored KCl Crystals

Journal of the Physical Society of Japan, 1960
Hiroshi Ohkumura, Katsunobu Awane
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