[en] The influence of some admixtures and γ-irradiation on the character of optical and electrical phenomena acompanying the LiF crystal disruption was investigated. The crystals were studied for absorption spectrum flow limit and electric conductivity. Increased VO₂(NO₃)₂ concentrations cause a smooth rise in the flow limit. Alterations in the concentration of flaws in the crystal Zlattice lead to changes in mechanical characteristics and triboluminescence intensity. Electrization of crystal surface decreases when concentration of flaws increases

[en] The effects of stressed states of crystals in the presence therein of various flaws on electron thermoluminescence and thermoexoemission were studied. Bure LiF crystals and LiF crystals with admixtures of U, Mg, Hg, Fe and In were used in the work. Heat emission spectra are shown for non-deformed and plastically deformed samples. Heat treatment essentially affects the spectral characteristics of heat emission. The admixtures sharply change the character and overall intensity of thermoluminescence and thermoemission spectra. X-ray treatment of pure and admixed LiF crystals also essentially affects those specta. LiF crystal hardening at large irradiation doses gives rise to the assumption that the irradiation hardening is basically caused by formation of vacancies in the bulk of a crystal

[en] Volumetric disruption at minimum irradiation energy of a ruby crystal laser was studied, and crystal reaction to the laser action was also examined. LiF, NaF, KCl, RbCl and KBr crystals were used in the experiment. Luminescence at disruption of all the crystals studied was found to have a continuous spectrum. Minimum breaking energy changed depending on the crystal used. In cases when the laser flux density was insufficient to cause breaking, irreversible changes occurred in the laser, indicating the appearance of electric charges. The charges were presumably caused by plastic deformation due to a shock wave initiated by irradiation of the laser whose energy was still insufficient to cause disruption

[en] Aniotropy of low-frequency electrooptical properties of lithium iiodate crystals has been investigated in terms of a nonlinear refraction index. Results of the data comparison on the permittivity dispersion and on the nonlinear refraction index shown that processes of establishing a linear and nonlinear polarization of lithium odate in the frequency range up to 10¹⁷ Hz are of different nature

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[en] Ranges of crystallization of Y₃Fe₅O₁₂ and phases borderind on it in the P-Y₂O₃-Fe₂O₃ pseudoternary system (P being the sum of PbO, PbF₂ and B₂O₃ moles) are plotted during varying the solvent composition in the following ranges: PbF₂ from 0.5 to 2; B₂O₃ - from 0.2 to 0.65 mol. relatively to 1 mol. PbO. On the basis of this diagrams chemical interactions between solution components are analyzed; and alongside with formerly known YFeO₃, Fe₂O₃, PbFe₁₂O₁₉, the Y₄O₃F₆ phase is separated. It is shown that the highest solubility of Y₃Fe₅O₁₂ takes place in the compositions enriched by PbF₂. The values of Y₃Fe₅O₁₂ mass growth rate on seeds in solutions - melts with the concentration of 3-5 and 12-16 weight%, which are 0.01-0.04 and 0.2-0.3 g/hr, respectively, are presented

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[en] Crystallization of Y₃Al₅O₁₂xNd₃sub(-) on planar Y₃Al₅O₁₂ seeds oriented allong the fast-growing directions (at an angle to < 110 > > 112 > axes) is studied. Crystallization has been carried out from diluted (3-8%) solution-melts based on lead compounds: PbO-PbF₂ and PbO-PbF₂-B₂O₃ in the low-temperature region ( < 1000 deg C) by gradual decrease of solution temperature. The smooth surface of the seed becomes rough during the process of growth. The volume of the crystal mainly increases due to growth of the rough faces. Growth of rough crystal faces without trapping of solution marcoinclusions occurs at growth rates < 10 mcm/h. At higher rates solution is trapped in polyhedral angles of the rough surface. In the low-temperature region ( < 1000 deg C) crystal growth is accompanied by inclusions of particles of colloidal sizes. Above 1050 deg C in conditions of intensive agitation of solution colloidal inclusions are not trapped