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[en] Consideration is given to results of studies of photoinduced changes of magnetic permeability in monocrystals of yttrium-ferrite garnet, grown from BaO-B₂O₃ solvent without any alloying additions. Photoinduced change of permeability in examined samples in 77-200 K range is considered to be irreducible under experiment conditions. Improvement of time characteristics of reversible photoinduced effect is possible in the case of increase of probability of photoinduced center occurence with decrease of activation energy

[en] Short note. 4 refs.; 1 fig.; 1 tab

[en] Solubility of Y₃Al₅O₁₁ in PbO-xPbF₂ (x=0.5; 1; 2) and phase formation in the system Y₂O₃-Fe₂O₃-PbO-PbF₂-B₂O₃ in a low temperature region (750-1100 deg C) have been studied. Solubility of Y₃Al₅O₁₂ increases with PbF₂ content in the solution. When the content of lead fluoride (PbO-2PbF₂) in the solvent is high, different solubility is observed for different methods of solution preparation. It has been shown for the system Y₂O₃-Fe₂O₃-PbO-PbF₂-B₂O₃ that in solvents with similar composition, as compared with high-temperature region, the solubility of the initial oxides changes (solubility of Y₂O₃>solubility of Fe₂O₃) as well as the order of phase formation in the system (YBO₃ and Fe₂O₃ crystallize prior to garnet). The crystals Y₃Al₅O₁₂ and Y₃Fe₅O₁₂ have been grown on the oriented seeds of alumoyttrium garnet

[en] This paper outlines the basic trends in the flux growth of crystals using as examples iron garnets and other incongruently melting compounds. Spontaneous crystallization in large and small volumes is discussed. The localization of crystallization centers makes it possible to grow sufficiently large crystals but the number of crystallization uncontrollable. Consequently, both large and small crystals grow simultaneously. The flux growth of large crystals by the accelerated crucible rotation technique is reviewed

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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

[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