Method of growing febo3 single-crystal film on diamagnetic substrate

FIELD: chemistry.

SUBSTANCE: charge is fused in a platinum crucible, the components are taken at a ratio, wt %: Fe2O3 - 5.37, B2O3 - 51.23, PbO - 29.31, PbF2 - 13.73. Thereinafter, the crucible with the melt-solution is placed in a growth furnace, heated to 900-950°C and maintained with stirring at said temperature for a day. Then the temperature is quickly reduced to 820-830°C, the diamagnetic crystal GaBO3 is dipped into the melt-solution fixed on the chip carrier and maintained for 0.5-3 hours with stirring. Then the temperature is lowered slowly at a speed of 3-40°C/h to 800°C, and the chip carrier is removed from the furnace.

EFFECT: invention allows to obtain a single-crystal film FeBO3 on the diamagnetic substrate GaBO3.

3 dwg, 3 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of producing polymer nanocomposites in form of thin films for superdense information recording involves producing a precursor consisting of polyvinyl alcohol, water and a mixture of water-soluble salts of ferric and ferrous iron, followed by treatment with at least one water-soluble dialdehyde at pH 0-3 in the presence of an acid as an acidifying agent, obtaining a thin film on a dielectric nonmagnetic substrate depositing the precursor on a substrate rotating on a centrifuge to form a gel film, treating the obtained gel film with an alkali, the alkali being added in an amount allows complete alkaline hydrolysis of the mixture of iron salts to form a mixture of magnetite or maghemite. The obtained gel film is treated with the alkali in ammonia vapour which is formed from aqueous ammonia solution (NH4OH) or hydrazine hydrate (N2H4·H2O) for 5.0-15.0 hours.

EFFECT: reduced particle size dispersion of magnetite and maghemite nanoparticles, obtaining a nanocomposite with a uniform structure, the obtained structure can be used as storage medium for superdense magnetic information recording.

2 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: evaporative material includes a core made from high-melting metal with thermal capacity per unit volume of at least 2 MJ/K·m3 and having through holes. The core is coated with rare-earth metal or its alloy by melting of rare-earth metal or its alloy, submersion of the core into a molten bath of rare-earth metal or its alloy, extraction of the core from it and hardening of molten rare-earth metal or its alloy on the core surface. A method for obtaining the above evaporative material involves formation of a solidified body from rare-earth metal or its alloy by melting of rare-earth metal or its alloy, submersion of the base made from high-melting metal having thermal capacity per unit volume of at least 2 MJ/K·m3 to molten bath of rare-earth metal or its alloy at maintaining the base at the temperature below the fusion temperature of rare-earth metal or its alloy and further extraction of the base with formation on the base surface of solidified body, separation of solidified body from the base and treatment of separated solidified body till plate-like shape.

EFFECT: obtaining evaporative material for manufacture of magnets with increased coercitive force, which can be treated till plate-like shape.

13 cl, 10 dwg, 3 ex

FIELD: producing conducting layer of variable magnetization and coercive force along conductor or conductors by means of material spraying unit.

SUBSTANCE: proposed method for producing substrate to be used in code-dependent systems and locks incorporating provision for identifying not only shape but also magnetization distribution and coercive force of conductors includes formation of conducting layer on substrate by means of material spraying unit that has vacuum chamber, source of material to be sprayed, gas ion source at whose output ion arcs unequally bombard source of material to be sprayed so that stream of knocked-out atoms or ions of sprayed material on one end of source dominates over that of sprayed-material knocked-out atoms or ions on other end of source; conducting layer formed on sprayed substrate has varying magnetization and coercive force along direction of conductor or conductors.

EFFECT: enhanced reliability and protection of layers being identified against counterfeit.

1 cl, 1 dwg

FIELD: applied superconductivity.

SUBSTANCE: proposed method that can be used for manufacturing mechanically loaded superconductor windings designed for sustaining conductor stress higher than 100 MPa as well as superconductor windings and devices designed for operation under variable conditions, such as superconducting magnets for charged particle accelerators and superconductor inductive energy storages involves use of liquid epoxy resin as filler doped with finely dispersed powder of rare-earth intermetallide, for instance HoCu2 (holmium-copper) or CeCu2 (cerium-copper). Filler concentration is chosen between 20 and 50% of liquid epoxy resin volume.

EFFECT: enhanced performance characteristics of superconductor windings under variable conditions.

4 cl, 2 dwg

The invention relates to the field of growing single-crystal films

FIELD: chemistry.

SUBSTANCE: invention relates to the field of the chemical technology of growing sodium-bismuth molybdate NaBi(MoO4)2 crystals for the research of physical properties and practical application. The monocrystals NaBi(MoO4)2 are grown by crystallisation from a high-temperature solution in a charge melt, which contains sodium-bismuth molybdate and a solvent sodium dimolybdate in a ratio, equal to 10-30:90-70 mol% respectively, crystallisation is carried out on inoculum, oriented perpendicularly to dipyramide edges [101], with the inoculum revolving at a rate of 10-30 rev/min and a rate of extension of 1-5 mm/day, with constant cooling of the solution-melt at a rate of 0.5-15 degrees/day, with growing being carried out under conditions of low gradients ΔT/Δl lower than 1 degree/cm in the solution-melt.

EFFECT: method makes it possible to obtain colourless, stoichiometric in the structure, large (size 75×30 mm), optically homogenous NaBi(MoO4)2 crystals.

1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to chemical technology and concerns manufacturing crystals of rubidium-bismuth molybdate RbBi(MoO4)2. The crystals RbBi(MoO4)2 are grown from a high-temperature solution in melted charge containing rubidium dimolybdate and triple lithium-rubidium-bismuth molybdate LiRbBi2(MoO4)4, in ratio of the latter toribidium dimolybdate equal to 10-40: 90-60 mole %, respectively; fuse crystallisation is focused in the direction [001], with a fuse rotation at 30-65 rpm and pulling rate 0.3-1.0 mm/day with cooling the melted solution at 0.2-1.0 degrees/day; the growing process in performed in the environment of low gradient ΔT less than 1 degrees/cm in the melted solution.

EFFECT: invention enables producing the coarse crystals RbBi(MoO4)2 of high optical quality.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to field of chemical technology, namely to growing crystals of potassium-barium molybdate K2Ba(MoO4)2 from solution-melt of K2Ba(MoO4)2 for analysis of physical properties and practical use. As solvent used is potassium molybdate K2MoO4, with molar ratio of potassium-barium molybdate and potassium molybdate K2MoO4, equal 1:2, respectively, crystallisation is carried out on seed, increased from 1 to 2 mm/day and rotating at rate 30-40 rev/min, oriented by direction [001], cooling of melt is carried out at rate from 0.2 to 3 degrees/day, with cooling of crystals being carried out at rate 20 degrees/day.

EFFECT: claimed method makes it possible to obtain optically homogenous K2Ba(MoO4)2, crystals of large size (25×15 mm) without inclusions, blocks and cracks.

1 ex

FIELD: chemistry.

SUBSTANCE: method for synthesis of tetragonal iron tellurides and iron tellurides doped with silver and/or sulphur includes placing a mixture of tellurium, selenium, sulphur and iron at one end of a sealed ampoule, filling the ampoule with a mixture of a eutectic composition of different combinations of sodium, potassium, rubidium and caesium chlorides, heating the ampoule with a temperature gradient from a temperature of 600-790°C at the side where the mixture is located to a temperature which is 30-100°C lower at the opposite side, during a time which enables to transfer the mixture to the opposite end of the ampoule.

EFFECT: invention enables to obtain large monocrystals of FeTe, including FeTe doped with selenium or sulphur, which are promising superconductors, without violating the integrity of the structure with low synthesis temperature.

1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to field of chemical technology and deals with obtaining volumetric crystals with composition Li8Bi2(MoO4)7. Crystals are grown from solution-melt of lithium-bismuth molybdate in solvent by crystallisation with gradual cooling of melt and grown crystals, and as solvent used is eutectic mixture, containing 47 mol.% of molybdenum oxide and 53 mol.% of lithium molybdate with content of lithium-bismuth molybdate and eutectic mixture equal 10-40 mol.% and 90-60 mol.% respectively, growing is performed under conditions of low temperature gradients, constituting less than 1 grad/cm, on primer, oriented by [001] and rotating at rate 20-30 rev/min with pulling rate 0.5-2.0 mm/day with constant cooling of solution-melt at rate 0.2-5.0 degree/day with further separation of grown crystals from solution-melt and cooling them to room temperature.

EFFECT: invention makes it possible to obtain large (with size 20÷30 mm) Li8Bi2(MoO4)7 crystals of high optic quality.

1 ex

FIELD: metallurgy.

SUBSTANCE: proposed method of crystal growth from the melt or solution-melt comprises crystal growth at starting bar locked at crystal holder at melt surface top point, growing the crystal in growth crucible at slow temperature decrease and cooling the grown crystal. Note here that, after growth cycle, melt or solution-melt remained in crucible is drained via pipe heated by extra heater arranged at crucible bottom while grown crystal is cooled in crucible without melt. Lithium triborate crystal sized to 150×130×80 mm is thus produced with optically qualitative part makes 80-90-volume of grown crystal.

EFFECT: ruled out cracking of grown crystal and deformation of platinum crucible melt in slow cooling.

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of growing lithium-magnesium molybdate Li2Mg2(MoO4)3 crystals. The method involves melting lithium-magnesium molybdate in a molten solvent, crystallising while cooling the melt and cooling the grown crystals, wherein the solvent used is lithium molybdate Li2MoO4 with molar ratio of lithium-magnesium molybdate to lithium molybdate Li2MoO4 of 2:3, respectively; crystallisation is carried out on an inoculating crystal revolving at a rate of 35 rpm, oriented on the [010] direction, rate of drawing rate of the inoculating crystal of 1-3 mm/day while simultaneously cooling the melt at a rate of 0.2-5 degrees/day and then separating the grown crystals from the melt and cooling at a rate of 30 degrees/hour.

EFFECT: method enables to obtain optically homogeneous lithium-magnesium molybdate crystals which do not contain inclusions, blocks and cracks.

FIELD: electrical engineering.

SUBSTANCE: according to the method, charge stock containing a gallium source and flux components is heated and maintained at the specified temperature or, alternatively, heated and slowly cooled down from the specified temperature inside a container, with a temperature gradient maintained between the upper and the lower parts of the container under a nitrogen-containing gas pressure. The flux, by way of core components, contains cyanides or cyanamides or dicyanamides of alkaline and/or alkaline-earth metals and modifying additives enhancing gallium nitride solubility and/or increasing growth rate and/or enabling control of physical properties of crystals obtained.

EFFECT: reduced rate of corrosion of the latter, improved quality of monocrystals obtained.

16 cl, 2 tbl

FIELD: chemistry.

SUBSTANCE: method involves dissolving the starting mixture, homogenisation thereof, placing a revolving single-crystal seed into the solution and growing a crystal, wherein the starting mixture contains 40 wt % beryllium aluminate with a chromium oxide additive in amount of 1-60 wt % of a solvent which consists of 95-98 wt % lead oxide and 2-5 wt % boron oxide, and the crystal is grown at temperature of 1250°C, axial temperature gradient of 2-20°C, drawing rate of up to 5 mm/day and rotational speed of up to 10 rpm.

EFFECT: obtaining bulk monocrystals of alexandrite of optical quality with low dislocation density.

2 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to process of production of mono crystals of high temperature superconductors (HTSC) of "123" type, required for experimental research of fundamental properties of HTSC, and also for manufacture of instruments and devices of superconducting electronics. A crucible with mixture of powders containing 1 weight share of preliminary synthesized high temperature superconducting material of "123" type and 5÷15 weight shares of eutectic mixture of barium oxide and copper oxide are heated in a furnace to temperature of mixture melting, and conditioned at this temperature during 20-50 hours in a uniform temperature field. Crystals are being grown during crucible containing mixture cooling at presence of horizontally directed temperature gradient. Crucible with mixture heating and conditioning is performed at temperature 1000±5°C. Directly before cooling the crucible with the said mixture is gradually set off during 10÷15 minutes into a furnace area with horizontal temperature gradient 9÷11 °C/cm, maintaining constant temperature 1000±5°C of a hot wall of the crucible. Further, growth of crystals is performed by cooling the crucible with mixture at rate 0.5÷2°C/hour in constant temperature gradient.

EFFECT: production of mono crystals of HTSC possessing mirror surfaces and dimensions in plane ab more 1 mm.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the field of the chemical technology of growing sodium-bismuth molybdate NaBi(MoO4)2 crystals for the research of physical properties and practical application. The monocrystals NaBi(MoO4)2 are grown by crystallisation from a high-temperature solution in a charge melt, which contains sodium-bismuth molybdate and a solvent sodium dimolybdate in a ratio, equal to 10-30:90-70 mol% respectively, crystallisation is carried out on inoculum, oriented perpendicularly to dipyramide edges [101], with the inoculum revolving at a rate of 10-30 rev/min and a rate of extension of 1-5 mm/day, with constant cooling of the solution-melt at a rate of 0.5-15 degrees/day, with growing being carried out under conditions of low gradients ΔT/Δl lower than 1 degree/cm in the solution-melt.

EFFECT: method makes it possible to obtain colourless, stoichiometric in the structure, large (size 75×30 mm), optically homogenous NaBi(MoO4)2 crystals.

1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to chemical technology and concerns manufacturing crystals of rubidium-bismuth molybdate RbBi(MoO4)2. The crystals RbBi(MoO4)2 are grown from a high-temperature solution in melted charge containing rubidium dimolybdate and triple lithium-rubidium-bismuth molybdate LiRbBi2(MoO4)4, in ratio of the latter toribidium dimolybdate equal to 10-40: 90-60 mole %, respectively; fuse crystallisation is focused in the direction [001], with a fuse rotation at 30-65 rpm and pulling rate 0.3-1.0 mm/day with cooling the melted solution at 0.2-1.0 degrees/day; the growing process in performed in the environment of low gradient ΔT less than 1 degrees/cm in the melted solution.

EFFECT: invention enables producing the coarse crystals RbBi(MoO4)2 of high optical quality.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to field of chemical technology, namely to growing crystals of potassium-barium molybdate K2Ba(MoO4)2 from solution-melt of K2Ba(MoO4)2 for analysis of physical properties and practical use. As solvent used is potassium molybdate K2MoO4, with molar ratio of potassium-barium molybdate and potassium molybdate K2MoO4, equal 1:2, respectively, crystallisation is carried out on seed, increased from 1 to 2 mm/day and rotating at rate 30-40 rev/min, oriented by direction [001], cooling of melt is carried out at rate from 0.2 to 3 degrees/day, with cooling of crystals being carried out at rate 20 degrees/day.

EFFECT: claimed method makes it possible to obtain optically homogenous K2Ba(MoO4)2, crystals of large size (25×15 mm) without inclusions, blocks and cracks.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to field of chemical technology and deals with obtaining volumetric crystals with composition Li8Bi2(MoO4)7. Crystals are grown from solution-melt of lithium-bismuth molybdate in solvent by crystallisation with gradual cooling of melt and grown crystals, and as solvent used is eutectic mixture, containing 47 mol.% of molybdenum oxide and 53 mol.% of lithium molybdate with content of lithium-bismuth molybdate and eutectic mixture equal 10-40 mol.% and 90-60 mol.% respectively, growing is performed under conditions of low temperature gradients, constituting less than 1 grad/cm, on primer, oriented by [001] and rotating at rate 20-30 rev/min with pulling rate 0.5-2.0 mm/day with constant cooling of solution-melt at rate 0.2-5.0 degree/day with further separation of grown crystals from solution-melt and cooling them to room temperature.

EFFECT: invention makes it possible to obtain large (with size 20÷30 mm) Li8Bi2(MoO4)7 crystals of high optic quality.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of growing lithium-magnesium molybdate Li2Mg2(MoO4)3 crystals. The method involves melting lithium-magnesium molybdate in a molten solvent, crystallising while cooling the melt and cooling the grown crystals, wherein the solvent used is lithium molybdate Li2MoO4 with molar ratio of lithium-magnesium molybdate to lithium molybdate Li2MoO4 of 2:3, respectively; crystallisation is carried out on an inoculating crystal revolving at a rate of 35 rpm, oriented on the [010] direction, rate of drawing rate of the inoculating crystal of 1-3 mm/day while simultaneously cooling the melt at a rate of 0.2-5 degrees/day and then separating the grown crystals from the melt and cooling at a rate of 30 degrees/hour.

EFFECT: method enables to obtain optically homogeneous lithium-magnesium molybdate crystals which do not contain inclusions, blocks and cracks.

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