Crystal growth (C30)

C   Chemistry; metallurgy(318327)
C30            Crystal growth(2110)
ethod for growing alumino-yttrium garnet doped with vanadium // 2641828
FIELD: chemistry.SUBSTANCE: invention relates to a technology for the production of single-crystal materials for laser technology designed to modulate the quality of laser radiation (passive laser shutters - PLS). The method of growing alyumo-ittrium garnet doped with vanadium (AIG:V) is growing a crystal by the method of vertical directional solidification in a molybdenum crucible in a reducing atmosphere of argon with hydrogen, wherein the initial mixture further contains metallic chromium, the composition of the sample is determined from the general formula Y3(Al(1-0.01x)V0.03x/5Cr0.02x/5)5O12, where x is the concentration of vanadium in the octahedral and tetrahedral positions of the crystal lattice and is from 1 to 7 at. %. The result of the invention consists in reducing the concentration of the phase inclusions of molybdenum (a crucible material) of less than or equal to 10 mcm in the grown crystal AIG: V with a vanadium concentration greater than or equal to 3⋅1020 cm-3 up to the values that do not affect the optical quality of the PLS. The PLS based on the crystals AIG: V with a vanadium concentration of ≥3⋅1020 cm-3 provide Q-switching in the wavelength range of 1.02-1.45 mcm.EFFECT: improvement of the method, improvement of the properties of the crystals.2 dwg, 1 tbl
ethod of cleaning melt surface when growing germanium monocrystals // 2641760
FIELD: metallurgy.SUBSTANCE: essence of the invention consists in extraction of slags (oxide films) from the melt surface, and from crucible walls below the level of germanium melt in the crucible. The method consists in collecting the most part of all available oxide films on the melt surface and below melt level in the zone where it adjoins the crucible by sticking thereof to a preliminarily grown crystal. The result of efficient melt cleaning is achieved by adjusting the rotation speed of the crucible, crystal, the crucible position in a heat unit, as well as consumption of working gas (argon), wherein maximum high concentration of slag on the melt surface of crystal growth zone is achieved, and it facilitates their extraction on the preliminarily grown crystal. The preliminarily grown crystal is subjected to 2-5 cycles of sharp pulling with separation of the preliminary crystal from melt and then its subsequent complete immersion into the melt, which provides separation of slag impurities from the crucible below the melt level with subsequent floating thereof on the melt surface. Subsequent drawing up the preliminary crystal in each cycle provides collection of oxide films from the melt surface onto crystallisable surface of the ingot.EFFECT: yield of monocrystals with significantly lower dislocation density, reduced risk of twinning and polycrystallisation of the ingot during the growing process and reduced average time of the growth plant working cycle.2 cl, 2 ex
ethod for producing nanocrystalline powder of molybdenum oxycarbide // 2641737
FIELD: chemistry.SUBSTANCE: method of producing nanocrystalline powder of molybdenum oxycarbide includes evaporation of oxygen-containing compounds of molybdenum at a high temperature in an atmosphere containing an inert gas, followed by the condensation upon cooling. The powder of molybdenum trioxide is used as the oxygen-containing molybdenum compound, the evaporation is carried out in the presence of urea taken in the ratio of molybdenum trioxide: urea = 1:1, in terms of the plasma precondensation in the low-temperature nitrogen plasma at a temperature of 4000÷6000°C with the power of the plasma torch 2.4÷3.6 kWh at a flow rate of plasma 50÷55 m/s and a feed rate of powder of 150-200 g/h, and cooling is carried out in a stream of nitrogen, followed by the vortex cycloning and capture on the fabric filter.EFFECT: invention makes it possible to obtain molybdenum oxycarbide with a structure of the NaCl type without foreign impurities with a particle size of not more than 30 nm in an environmentally safe manner.2 ex, 2 dwg
ethod for obtaining doped diamond monocrystal // 2640788
FIELD: chemistry.SUBSTANCE: method of growing diamond single-crystals doped with nitrogen and phosphorus at high pressures of 5.5-6.0 GPa and temperatures of 1600-1750°C is carried out on the seed crystal, which is pre-pressed into a substrate of cesium chloride and separated from the source of carbon, nitrogen, and phosphorus with the metal-solvent, which is used as an alloy of iron, aluminium, and carbon. Between the source of carbon, nitrogen, and phosphorus and the seed crystal, a temperature difference of 20-50°C is created. The alloy of iron, aluminium, and carbon in the metal-solvent is taken with the following component ratio, wt %: iron 92.5-95.0; aluminium 2.5-0.5; carbon 5.0-4.0. The mixture of the source of carbon, nitrogen, and phosphorus is taken with the following component ratio, wt %: carbon (graphite) 95.0-97.0; phosphorus 5.0-3.0; adsorbed nitrogen 0.001±0.0005. Heating is carried out up to the initial temperature in a zone of growth at 100-250°C higher the melting temperature of the alloy of the metal-solvent, the exposure is produced at this temperature for 50 to 150 h. The mass flow rate of crystal growth is more than 2 mg/h. The technical result consists in the controlled doping the diamond single- crystal grown on the seed with impurities of phosphorus and nitrogen in the conditions of influence of high pressure and temperature.EFFECT: resulting large diamond single-crystals contain a nitrogen admixture in the concentration of 0,1-17,8 parts per million of carbon atoms and phosphorus in a concentration of 0,5-5 parts per million of carbon atoms.2 dwg, 3 ex

Nanotubular materials crystallising in system of k2o-tio2-x-h2o (x=nio, mgo, al2o3, cr2o3, co2o3, fe2o3) and method of their synthesis // 2640766
FIELD: chemistry.SUBSTANCE: nanotubular materials crystallising in the system of K2O-TiO2-X-H2O (X=NiO, MgO, Al2O3, Cr2O3, CO2O3, Fe2O3) are characterized by the fact that in their composition up to 10% of ions Ti4+ is replaced by doping two- or trivalent metal. The method of synthesis of nanotubular materials is characterized by the fact that the synthesis of the samples is carried out by hydrothermal treatment of a pre-prepared mixture of hydroxide in KOH solution, to produce the initial mixtures of hydroxides, a solution of titanyl chloride synthesised by reaction of TiCl4 with chilled distilled water, is mixed with aqueous solutions of salts of finished elements in a predetermined ratio, and then the precipitation of hydroxides is produced by adding NH4OH to the aqueous solution mixture at pH=9-9.5 followed by washing with distilled water, drying at 70-90°C and mechanical crushing, then the crushed precipitate is mixed with 10 M KOH solution and subjected to a hydrothermal treatment at 170-180°C for, at least, 24 hours, after which the resulting product is washed with distilled water.EFFECT: invention makes it possible to synthesise potassium-titanate nanotubes with an average outer diameter of 5 to 12 nm.2 cl, 5 dwg, 2 ex
Optical material of infrared range and method of its production // 2640764
FIELD: physics.SUBSTANCE: optical material is a single crystal indium InI monochloride of rhombic syngony with a spectral transmission region of up to 51 mcm. A method of producing InI includes a pre-treatment of the initial charge by rectification, the growing of the single crystal by Bridgman method at a speed of broach of not more than 2.0 mm/h in a quartz ampoule made of glass "Pyrex", the separation of the muddy part from the end part of the grown crystal and the fourfold crystal-physical clearance obtained at the previous stage of the high-purity material by re-growing the crystal with the intermediate separation of the end muddy part of the crystal after each cleaning.EFFECT: invention allows to obtain single crystals of InI, transparent from the visible to the far infrared range of the spectrum, non-hygroscopic.2 cl, 3 dwg, 1 tbl, 6 ex
ethod of producing red iron oxide pigment // 2640550
FIELD: chemistry.SUBSTANCE: method includes oxidative hydrolysis of aqueous solutions of iron sulphate (II) at a temperature of 15 to 40°C and pH of the reaction medium of 4 to 12 followed by hydrothermal treatment of the resulting suspension of iron oxyhydroxides (III) at a temperature of 160 to 230°C. And before the oxidative hydrolysis stage begins, additives are added to the reaction medium, which stabilise the crystal growth. Such additives are polyphosphates or sodium silicates in an amount of 1 to 50 mmoll per 1 mole of iron oxyhydroxide (III).EFFECT: improvement of qualitative indicators of the red iron oxide pigment due to reduction of its polydispersity in 1,25-1,4 times in comparison with the nearest analogue.1 tbl, 3 ex

anganite with colossal magnetoresistance in temperature range of 190-300 k // 2638983
FIELD: physics.SUBSTANCE: polycrystalline material based on lanthanum-strontium manganite has the composition La0.810Sr0.190Mn1-x(Zn0.5Ge0.5)xO3, where x takes values from 0.148 to 0.152. The material is made from a charge containing lanthanum oxide, carbonate strontium, manganese dioxide, zinc oxide, and germanium oxide. These components are mixed and spend primary grinding in a ball mill for 4 hours with subsequent heat treatment at a temperature of 1000°C for 4 hours. Secondary grinding in a ball mill is then carried out for 10 hours, moulding and sintering at a temperature of 1200°C for 10 hours. The resulting material has a positive effect on the colossal magnetoresistance achieved in the magnetic field up to 1 T and a gently varying in a wide temperature range from 190 K to 300 K.EFFECT: invention allows to reduce the cost of manufacturing manganite, to expand the operating temperature range of the devices based on it, eliminating the need for heat sensitive items, to provide increased reliability and reliability of measurements.1 dwg, 1 ex
Crystals based on thallium bromide for detectors of ionizing radiation // 2638863
FIELD: chemistry.SUBSTANCE: invention can be used as an optical material for IR optics, laser technology, acousto-optics. Crystals based on thallium bromide additionally contain 0.0028-0.00008 wt % of the magnesium bromide impurity. Material characteristics: μτe - 7.8⋅10-4 cm2/V, μτh - 2.5⋅10-4 cm2/V, resistivity - 1⋅1012 Om⋅cm.EFFECT: increasing the detector characteristics of the material, ensuring the stability of properties during operation.1 tbl

ethod of single-crystal growth and device for its implementation // 2638850
FIELD: technological processes.SUBSTANCE: method of single-crystal growth comprises supplying directed flow of gas-powder mixture from a device nozzle on a substrate with simultaneous melting of powder material of the gas-powder mixture on the substrate by a laser beam and moving the nozzle relative to the substrate, wherein in the process of welding the nozzle is moved relative to the substrate with a crystalliser with simultaneous lifting and the direction of its inclination angle or position in space is changed in such a way that infinitely continuous growth of single-crystal and predetermined change in its growth direction are carried out, wherein the process is carred out at the flow speed of the gas-powder mixture of 1-50 g/min, the linear speed of the laser beam movement of 0.1-50 mm/s, the laser radiation power of 0.5-10 kW and the nozzle displacement speed relative to the substrate of 0.001-30 m/s. The method is carried out in the device containing a laser unit, a nozzle 1 with an inlet branch pipe for supplying the gas-powder mixture 6 onto the substrate 4 and a fibre cable connected to the laser unit for transportation of the laser beam 7, a table 3 for positioning the substrate 4, a driving system for mutual displacement of the nozzle body relative to the table surface with the substrate 4. The device is provided with a crystalliser 2 located below the outlet of the nozzle 1 and representing a water-cooled branch pipe with at least one offset connected to the surface of the substrate.EFFECT: obtaining single-crystal products or products with directed crystals in the structure without size limitation, with a given orientation and form of a single-crystal.2 cl, 1 dwg

Cutting elements of drill bit with fixed cutters containing hard cutting plates made of synthetic diamonds formed by chemical vapour deposition // 2638220
FIELD: mining engineering.SUBSTANCE: method of forming a single crystal cutting element for the drill bit with fixed cutters includes transformation of graphite powder into diamond powder chemically precipitated from vapour phase (CVD); growing a plurality of CVD single crystal diamonds on a substrate, wherein said multiple CVD diamond single crystals are grown in orientation along a crystallographic plane, each CVD single crystal diamond of a plurality of CVD single crystal diamonds has a rectangular prismatic shape with sides width in the range from 10 to 20 um; removing at least a portion of the CVD single crystal diamonds from the substrate; transformation of the removed CVD single crystaldiamonds into powder of CVD single crystal diamonds; placing the powder of CVD single crystal diamonds and a tungsten carbide support element into a mould and thermomechanical treatment of the powder of CVD single crystal diamonds in a mould for forming a solid plate of CVD single crystal diamonds attached to the tungsten carbide support element.EFFECT: increasing the strength of the resulting structure at high temperatures and pressures.14 cl, 6 dwg
ethod of producing fine-grained barium titanate // 2637907
FIELD: chemistry.SUBSTANCE: method ofproducing fine-grained barium titanate comprises treating a mixture of titanium dioxide and barium oxide powders with water vapour in a reactor in a static mode under supercritical conditions: at a temperature of 380 to 420°C and a pressure of 22.5 to 30.5 MPa for 16-48 hours, after which the reactor is cooled to room temperature, the resulting barium titanate is first dried at a temperature of 70±20°C for 10-12 hours, washed with a solution of acetic acid with a concentration of 5-10 wt %, then with distilled water and again dried at a temperature of 70±20°C to constant weight.EFFECT: invention makes it possible to produce single-phase barium titanate with a crystal size of 40-300 nm with a high content of the basic substance.3 cl, 8 dwg, 2 tbl, 8 ex

Device for growing profiled crystals from solution // 2637018
FIELD: chemistry.SUBSTANCE: device comprises a hermetic crystalliser 3, a growth chamber 1 of rectangular cross-section with a seed crystal 2 and a solution supply system to the crystal 2 including a non-moving pump 5 for supplying a saturated solution to the growth zone of the crystal 2 and a plate 6 arranged above the growing surface of the crystal 2, which is reciprocable in the vertical direction and the progressivey upward direction as the crystal grows, having a width and a length less than the width and the length of the growth chamber 1 so that between the plate 6 and the walls of the chamber 1 there are slots connected to the actuator 7 by, at least, one variable length rod 8 with a fastening unit 9 to the plate 6 allowing the angle between the plate 6 and the rod 8 to be varied. It is also possible to make the plate 6 with holes for additional passage of the solution.EFFECT: simplification of construction, improvement of conditions for growing.2 cl, 4 dwg
ethod of producing complex cesium hydrosulfate phosphate of composition cs6 (h2so4)3 (h2po4)4 // 2636713
FIELD: chemistry.SUBSTANCE: composition is produced by solid-phase synthesis from charge with the molar ratio CsHSO4:CsH2PO4:CsH5(PO4)2, equal to 3:2:1, at a temperature of 60-90°C.EFFECT: cesium hydrosulfate phosphate in the form of a polycrystalline powder has a high value of proton conductivity and a lower value of the phase transition temperature.2 dwg

ethods of improving pcd sintering (polycrystalline diamond) using graphene // 2636508
FIELD: chemistry.SUBSTANCE: nanoscale mono- or multilayer graphene-containing material is sintered for about 5 minutes in the absence of a transition metal catalyst at a pressure and temperature of, at least, 45 kbar and 700°C, respectively. Alternatively, the said material is mixed with diamond seeding in an amount of not less than 0.01 wt % of the mixture before sintering. Graphene has a ratio of sizes from 500 to 2000. The resulting compacts of polycrystalline diamond and the cutting element comprise polycrystalline superabrasive particles, for example, diamond.EFFECT: invention avoids the harmful effect of the catalyst on the mechanical and abrasive properties of compacts and cutting tools.24 cl, 3 tbl, 7 dwg
ethod for obtaining zinc chalkogenides // 2636091
FIELD: metallurgy.SUBSTANCE: method comprises applying a film of alloying component of chromium 2-10 microns thick or 1 micron thick iron on the surface of zinc chalcogenid, forming a layer of the corresponding zinc chalcogenide on the film by chemical vapor deposition, and diffusion annealing of the resulting three-layer structure in argon at a pressure from 90 MPa to 200 MPa and temperature from 1100°C to 1350°C for 1-72 hours. Zinc chalcogenide is selenide or zinc sulphide.EFFECT: surface of the obtained alloyed samples has an increased resistance to laser breakdown.2 dwg, 2 ex

ethod of splicing components of polycrystalline diamonds in microwave plasma // 2635612
FIELD: physics.SUBSTANCE: invention relates to methods for producing monolithic joints of polycrystalline diamond rods intended for use in the manufacture of electronics, optics, and microwave devices, in particular, for the production of dielectric supports in travelling wave tubes (TWTs) using a low absorption coefficient at generation frequencies. The method of splicing the components of polycrystalline CVD diamonds in a microwave plasma is that the ends of the polycrystalline diamond (PCD) samples being connected are placed on an intermediate single crystal diamond substrate (ISCDS) on the growth face {100}, which is perpendicular to the direction of the spliced compound axis, towards to each other with a gap S not less than (0.5-5.0)⋅h, where h is a height of the PCD, while the ends of the PCD are made with bevels with an opening angle α(°)=tg(Ve.pcd.⋅τ)/(Ve.pcd/⋅τ), where τ - the total growth time of the welded joint, Ve.pcd is a speed of the oncoming growth of the layers on the PCD and on the lateral face {111} of the ISCDS, Ve.pcd is a rate of epitaxial growth of the single crystal diamond layer on the growth face {100} of the ISCDS. The monolithic compound is created by the method of simultaneous epitaxial accelerated and retarded growth of CVD layers on an intermediate single-crystal diamond substrate (ISCDS) and the spliced layers on the faces of the ISCDS and the spliced ends of the PCD perpendicular to the direction of the joint axis at the optimal distance from the base of the connected components, equal to half the opening angle of a monolithic one-piece connection α(°).EFFECT: invention provides a saving in time and money for growing large-size blanks, replacing them with less expensive smaller billets and satisfying the requirements of cutting out the support rod elements therefrom for the travelling wave tubes that acquire the desired length after splicing.2 dwg, 2 tbl, 1 ex
ethods of producing silicon-substituted hydroxyapatite and bioactive coating on its basis // 2635189
FIELD: chemistry.SUBSTANCE: method of producing silicon-substituted hydroxyapatite, including the synthesis of silicon-substituted hydroxyapatite by precipitation from aqueous solution of reagents containing orthophosphoric acid, calcium hydroxide and tetraethylorthosilicate, settling, precipitation, drying and heat treatment of the precipitate, characterised in that the heat treatment of the precipitate is carried out at the temperature of 200-250°C for 2-3 hours, then it is cooled for 1-2 hours, ground for 15 minutes and fractionation up to 90 mcm is carried out.EFFECT: increasing the adhesion and bioactivity through the use of silicon-substituted hydroxyapatite.2 dwg

ethod of producing monocrystalline sic // 2633909
FIELD: chemistry.SUBSTANCE: method includes sublimation of a SiC source placed in a crucible onto a seed SiC single-crystal plate placed on a flat ring support, and one or more layers are applied to the seed SiC single-crystal plate from the side not intended for growth of the SiC single-crystal ingot, providing the thermochemical stability and given temperature conditions on the surfaces of the plate of the seed SiC single-crystal, and the holder with a seed SiC single-crystal plate is installed in a crucible in such a way, that the surface of the plate, intended for the growth of the SiC single-crystal ingot, is turned into the inside of the crucible and contacts with the gaseous medium inside the crucible during sublimation. On the circumference of the inner cylindrical surface of the holder flat ring, protrusions with a width of h=(1-3)⋅t and a length of S=(1-10)⋅h are periodically made, the ends of which are provided with ledges with a depth of k=0.3-1 mm and a width of t=0.5-2.0 mm, for placing a seed SiC single-crystal plate with a thickness H exceeding the depth of the ledge k, and on top of the holder with a plate with the deposited layers a plate of thermally expanded graphite with a thickness exceeding the value (H-k) is placed, and then is fixed with a clamping element in the form of a rigid plate of 1.5-8 mm thick and a retaining ring of thermostable materials.EFFECT: improving the quality of the ingot, reducing the elastic stresses in the seed single-crystal plate, achieving a uniform growth rate over the entire surface of the seed single-crystal plate with the formation of an almost flat crystallization front.6 dwg, 1 tbl
ethod for producing epitaxial layers of cdxhg (1-x) te from tellurium-based solution // 2633901
FIELD: chemistry.SUBSTANCE: presented method for producing epitaxial layers of CdxHg1-xTe from the tellurium-based solution involves the growth of an epitaxial layer of CdxHg1-xTe (0.19<x<0.33) by the method of liquid-phase epitaxy in a sealed quartz ampoule at the temperature of 500÷513°C to the substrate of Cd1-yZnyTe (and 0.02<y<0.06) with the crystallographic surface orientation (111)B±0.5°, located horizontally above the layer of the liquid phase at the height of 1 to 2 mm, in conditions of forced cooling of the substrate/solution system to 6÷11°C depending on the desired thickness of the epitaxial layer, and the preliminary dissolution of the surface substrate layer in the superheated tellurium-based solution for not more than 2° relative to the liquidus temperature, from which the epitaxial layer is grown, wherein system cooling is carried out at the temperature reduction rate of 0.2÷0.5 deg/min, starting from the time of the substrate contact with superheated solution.EFFECT: producing epitaxial layers without deflecting the shape of the surface from the shape of the substrate surface.1 tbl

ethod for cd1-xznxte single crystals growing, where 0≤x≤1, for inoculation at high pressure of inert gas // 2633899
FIELD: chemistry.SUBSTANCE: invention relates to melt growing of Cd1-xZnxTe (CZT) single crystals, where 0≤x≤1 for inoculation, by the OTF-method. The CZT crystals growing method is implemented under high inert gas pressure, under conditions of an axial heat flow near the crystallisation front, by the OTF method, using a background heater and immersed heater - OTF heater 6, by drawing crucible 1 with the melt into the cold zone ν at a rate for different initial compositions of charge 5, 7 in the crystallisation zone W1 with a melt layer thickness h, and in the make-up zone W2, as well as using probe 3 to control the melting point of the charge in the crystallisation zone W1. To obtain macro- and microhomogeneous CZT single crystals of a given crystallographic orientation, a single-crystal Cd1-xZnxTe inoculation of the desired crystallographic orientation 2 is installed at the bottom of crucible 1, probe 3 is placed in the center of inoculation 2 and charge 5 is placed, the composition of which ensures, with allowance for the partial melting of inoculation 2 and in accordance with the phase diagram of the CdZnTe system, the growth of the Cd1-xZnxTe single crystal at a given thickness of the melt layer h in the crystallization zone W1, then OTF-heater 6 is installed, charge 7 of a composition equal to the composition of inoculation 2 is placed above OTF-heater 6, forming the make-up zone W2, then the OTF crystalliser with crucible 1, inoculation 2, charge 5, 7 and OTF-heater 6 with probe 3 are placed in the growth furnace, the furnace is filled with an inert gas and the OTF-crystalliser is heated in the furnace in a vertical temperature gradient at a rate of 10-50 deg/hr until the top of inoculation 2 begins to melt, and then probe 3 is lowered to contact the non-melted part of inoculation 2, then heating is stopped and probe 3 is moved up to the level of the OTP-heater 6 bottom, the system is kept for 1-5 hours, controlling the melting rate of inoculation 2 by probe 3, after which the crystal begins to grow by pulling crucible 1 down at a rate of 0.1-5 mm/hr relative to stationary OTF-heater 6 with probe 3. When crystals are grown using a probe for controlling the inoculation melting point, it is possible to increase the yield percentage, obtain single crystals of a given crystallographic direction, and improve the quality due to monocrystallinity and resulting absence of blocks and twins. The average density of etch pits was 5* 103 cm-2 before crystal annealing. 89-92% of the crystal volume is single crystal, i.e. without blocks and twins, deviations from the specified composition in the volume were 0.5 at %.EFFECT: grown CZT crystals are characterized by a high degree of macro- and micro-homogeneity.13 cl, 1 dwg

agnetic-sensitive composite // 2633538
FIELD: physics.SUBSTANCE: magneto-sensitive composite consists of indium, antimony, and manganese and is a two-phase system corresponding to the formula (InSb)1-x(MnSb)x, where x=0.04-0.1. This system is obtained by the thermal treatment of indium antimonide and manganese antimonide at the temperature of 550 to 800°C.EFFECT: invention allows to obtain a magneto-sensitive composite with a high value of the magneto-resistance in magnetic fields from 0,15 T due to the increased content of manganese antimonide and high values of the Curie temperature from 540 to 570 K.1 dwg, 1 ex

Device for refining silicon // 2632827
FIELD: chemistry.SUBSTANCE: device for refining silicon by separating metal impurities on the metal surfaces of the crystalliser is made in the form of the rotation bodies, the crystalliser consists of a circular straight cylinder 1 located along the vertical axis of symmetry and cylindrical tubes 2, 3 coaxial with respect to it, connected by horizontal cross-shaped screeds 4, 7 in the surface and bottom layers of the melt 5.EFFECT: invention allows to produce high-quality raw materials with a low content of impurities.2 dwg
ethod for producing needle monocrystals of molybdenum vi oxide vi moo3 // 2631822
FIELD: chemistry.SUBSTANCE: surface of the molybdenum tape, securely fixed with its ends and arched upwards in the form of an arch, is heated by resistive, inductive or radiation exposure to a temperature of 650-700°C in an oxidizing gaseous environment containing from 10 to 40% of oxygen and an inert gas or a mixture of inert gases at a pressure exceeding 100 Pa, maintained at this temperature for at least 10 s from the moment of the occurrence of MoO3 vapours of white colour, then the heating is stopped and molybdenum tape is cooled to 25°C, after which the heating is resumed at a temperature of 650-700°C up to the formation on the ends and the surface of molybdenum tape from MoO3 vapours of thin needle monocrystals of molybdenum oxide with length up to 5 mm.EFFECT: resulting crystals are easily separated from the workpiece in the form of a tape, have a high degree of purity and structural perfection.2 ex

ethod for growing single crystals of profiled radial germanium // 2631810
FIELD: metallurgy.SUBSTANCE: method includes placing in a crucible a vertical form-builder with holes in area where its lower part adjoins the crucible for removal of excessive melt formed during crystallisation, placing horizontal forming elements of convex-concave shape in grooves of the vertical form-builder, loading initial charge into the vertical form-builder, heating thereof with formation of melt, immersion of seed crystal into the melt, growing crystal by reducing temperature at simultaneous drawing, stopping vertical drawing of crystal and further growing of crystal up to complete melt crystallisation, wherein increase of crystal in radius from moment of drawing stopping to full melt crystallisation is carried out by means of total temperature reduction, simultaneously performing melting and flattening the crystal caused by temperature increase and decrease with amplitude ±3°C for a period of 20 minutes. This growth mode leads to reduction in concentrations of structure major defects and associated optical inhomogeneities and physically equivalent to further annealing during crystal formation.EFFECT: enhanced structural and optical quality of large-sized single crystals in the form of a blank, maximally close to the shape of manufactured lenses and other optical elements, acoustic-optical and photoelectric devices based on germanium.3 dwg, 2 ex

ethod for obtaining zinc halcogenides allowed by transition metals // 2631298
FIELD: physics.SUBSTANCE: at least, one layer of the film containing, at least, one doping transition metal (chromium, cobalt, iron, manganese) is deposited to, at least, a part of the surface of, at least, one element of zinc chalcogenide. Further, the elements are stacked on each other to form a predetermined alternation of zinc chalcogenides and doping transition metals over the cross-section of the element such that, at least, two elements of zinc chalcogenide contact each other through, at least, one layer of the deposited film. The stacked elements are diffusively welded with subsequent diffusion annealing. The obtained samples have improved optical characteristics.EFFECT: reducing the time of obtaining samples and the number of technological stages, using the obtained zinc chalcogenides as an active medium reduces the laser generation threshold and increases the quantum efficiency of laser generation.6 cl, 6 dwg, 3 ex
ethod for producing monocrystals of monoclinic hafnium dioxide // 2631080
FIELD: chemistry.SUBSTANCE: method comprises interaction of metallic hafnium placed inside a quartz ampoule serving as an oxygen source with carbon tetrafluoride, which fills the ampoule after its evacuation, and heating of the sealed ampoule with the above mentioned reagents at a temperature of not more than 1200°C for at least 24 hours, while the metallic hafnium is placed in a quasi hermetic cartridge made of nickel or thermally expanded graphite with an opening of not more than 2-6 mm2 and placed inside the quartz ampoule, which is filled with carbon tetrafluoride to a pressure of not more than 250 torr.EFFECT: possibility of obtaining monocrystals of monoclinic hafnium dioxide of large size due to slow growth as a result of limited diffusion of gaseous hafnium fluorides through a small-diameter hole in a cartridge made of a material inert to carbon tetrafluoride and hafnium tetrafluoride.2 cl, 2 dwg, 3 ex

ethod of forming hollow single-crystal cylindrical tubes // 2630811
FIELD: electricity.SUBSTANCE: method of forming hollow single-crystal cylindrical tubes includes growing melt-cylindrical single crystals by pulling up with a single-crystal seed of the required orientation, separating two blanks of the required length from the single crystal, their mechanical and electrochemical machining, resulting in two hollow polyhedron cylinders with a predetermined geometry, determining the location of the desired crystallographic directions on the surfaces of the said cylinders, spark cutting and removing portions of cylinders with an intermediate crystallographic orientation, after which the remaining cylinders are rotated relative to each other about the longitudinal axis, joined, the cylinders are matched by electron beam welding, then the technological areas are separated by spark cutting from the workpiece, and electrochemical processing of welded mono-faceted single-crystal cylinder is performed.EFFECT: invention allows to obtain tubes with a homogeneous mono-faceted crystallographic orientation of the working surface and isotropic physico-mechanical properties.10 dwg

Crystalline material for recording x-ray radiation // 2630511
FIELD: chemistry.SUBSTANCE: invention relates to the method of producing a crystalline material that is a solid solution of the general formula Ba4-xSr3+x(BO3)4-yF2+3y, where 0≤x≤1 and 0≤y≤0.5 suitable for recording X-ray radiation. Crystalline material Ba4-xSr3+x(BO3)4-yF2+3y has colour centres formed under the influence of X-rays - stable hole centres [(BO3)O]4-, stable at room temperature for, at least, three months, causing absorption in the visible region of the spectrum and changing the colour of the crystals to dark violet and relaxation after irradiation with an intense light source with the wavelength of 300-400 nm.EFFECT: low hygroscopicity, can be synthesized in air in the absence of highly toxic elements.5 dwg, 2 ex

Crystalline body, optical device having crystalline body and method of manufacturing crystalline body // 2630123
FIELD: physics.SUBSTANCE: crystalline body, comprised of grenade type single crystal, has a couple of translucent surfaces that resist each other and reflect light, and, at least, one lateral surface that connects a couple of passing light surfaces. The ratio B/A of density A (amount of 1 cm2) of dislocations in translucent surfaces and density B (amount of 1 cm2) of dislocations in lateral surface meets the following general formula: 1≤(B/A)≤3600.EFFECT: obtaining single crystals of garnets and optical instruments with such crystals with a satisfactory extinction coefficient.11 cl, 17 dwg, 2 tbl, 6 ex
ethod of producing a small-crystalline aluminate of magnesium // 2630112
FIELD: chemistry.SUBSTANCE: method comprises the autoclaving of the initial mixture of water in the autoclave, comprising a molar ratio of 1.0-1.2 oxyhydroxide or aluminium hydroxide with magnesium oxide and an activating additive, which uses an aqueous solution of glycerol (C3H5(OH)3) and aluminium chloride⋅ AlCl3⋅6H2O. The treatment is carried out first under subcritical conditions, at a temperature of 200 to 360°C and steam pressure from 1.5 to 19 MPa for 6-20 hours, and then under supercritical conditions, water vapor at a temperature of 370 to 420°C and steam pressure from 21.5 to 30.4 MPa for 1-12 hours, after which the water vapor is removed, the autoclave is cooled to room temperature, the magnesium aluminate obtained is discharged, washed with distilled water until a pH of 7 washing waters is obtained and dried at temperature up to 70°C to constant weight, while glycerin is taken in an amount of 1-12 wt %, and aluminium chloride in an amount of 0.01-0.8 wt % relative to the weight of the final product, magnesium aluminate, the weight ratio of aluminium chloride to glycerol being 0.01-0.1. A mixture of magnesium oxide powders and hydroxide or aluminium oxyhydroxide can be preliminarily sifted or processed in a planetary or ball mill to form a homogeneous mass.EFFECT: invention makes it possible to obtain a single-phase fine-crystalline magnesium aluminate with an average crystal size of 0,2-0,5 mcm and a content of the main substance of not less than 99,99 percent.2 cl, 1 dwg, 1 tbl, 6 ex

Holmium-manganese sulfide with giant magnetoresistance // 2629058
FIELD: physics.SUBSTANCE: holmium-manganese sulfide with giant magnetoresistance includes manganese and sulfur and further contains holmium at the following ratio of components, wt %: holmium 2.5-15, manganese 47.5-35, sulfur 50.EFFECT: invention allows to obtain a magnetic compound with a cubic lattice of NaCl type, which has a stable and repetitive effect of giant magnetoresistance in a wide range of temperatures and magnetic fields.4 dwg, 2 tbl
ethod of crystalline diamond particles obtaining // 2628617
FIELD: nanotechnology.SUBSTANCE: method of crystalline diamond particles obtaining includes adding of cycloalkane (cyclic saturated hydrocarbon) or polybasic alcohol in an amount of 5-85 wt % the weight of detonation nanodiamonds to the nanodiamonds powder obtained by detonation synthesis, aging of the resulting composition at a static pressure of 5-8 GPa and a temperature of 1000-1800°C for 5-120 seconds and separating the resulting particles from graphite by sedimentation in the liquid.EFFECT: invention allows to directly obtain crystalline diamond particles of the size needed for finishing and biomarkers in the range of 50-500 nm, thereby eliminating the need for additional grinding.4 cl, 1 dwg, 25 ex

ethod for producing europium (ii) euf2 difluoride crystals // 2627394
FIELD: chemistry.SUBSTANCE: method for producing europium (II) EuF2 difluoride crystals is carried out in two stages, at the first of which EuF3 is pre-melted and its melt is fluorinated to remove the impurity of oxygen, after cooling the melt, the fluorinated EuF3 is milled and mixed with the pre-prepared crystalline silicon powder (Si) to produce the batch of the desired composition in accordance with the equation 4EuF3+Si=4EuF2+SiF4↑. At the second stage, the produced batch is melted, homogenized and the batch melt is crystallised by directional crystallisation using a fluorine-containing atmosphere, producing single-crystal europium EuF2 difluoride boules. As a directional crystallisation method, for example, the Bridgman-Stockbarger method is used. The fluorine-containing atmosphere in the crystallisation process is created by the decomposition of ammonium hydrofluorides or alkaline-earth elements. At the first step, the silicon powder can be introduced directly into the EuF3 melt with the aid of a dispenser ensuring compliance with a predetermined relationship between EuF3 and silicon.EFFECT: increasing the yield.4 cl, 3 dwg, 1 ex

Scintillator // 2627387
FIELD: physics.SUBSTANCE: invention relates to a scintillator that can be used as an X-ray detector in medicine, when inspecting things at airports, inspecting cargo in ports, in oil prospecting. The scintillator contains a CsI crystal as its base and Tl, Bi and O, wherein the concentration a Bi with respect to Cs in the crystal is 0.001 atomic million-1 ≤a≤ 5 atomic million-1; and the ratio (a/b) of the concentration a Bi with respect to Cs in the crystal to the concentration of b O with respect to I in the crystal is of 0.005⋅10-4 to 200⋅10-4.EFFECT: scintillator has a high output at high afterglow characteristics.2 cl, 4 dwg, 1 tbl, 12 ex
ethod for growing high-temperature monocrystals by sinelnikov-dziov's method // 2626637
FIELD: chemistry.SUBSTANCE: method involves melting the initial charge in the crucible and the subsequent growth of the single crystal with a seed while cooling the melt and then cooling the grown single crystal, while the crucible is made of a refractory material with a melting point above 2300°C the formulator with convection in the bottom and discharge in the side parts of the slits, the polycrystalline material or polycrystal obtained by melting in a cold crucible or fragments of a single crystal of the corresponding oxide is used as the initial charge, and the growth of single crystals is carried out at a rate from 0.5 to 4 mm/H.EFFECT: improving the quality of grown single crystals, the variety of forms obtained while reducing material and time costs, the possibility of growing single crystals both doped and without impurities.16 cl, 9 ex

ethod of determination of conditions of crystalisation of proteins // 2626576
FIELD: chemistry.SUBSTANCE: method of crystallisation of proteins involves preparation of the initial solutions of the protein in the buffer, filtration of the resulting solution, centrifugation and filling with a solution of capillaries. The first part of the protein solutions obtained after centrifugation is mixed with the buffer solution in equal volumes, and the remaining second part is subsequently used for mixing with the precipitant. The first part of the protein solutions is analysed by small-angle of X-ray scattering to obtain a series of scattering curves, the curves are analysed and the size of a single protein subunit in each of the solutions of different concentrations is calculated. The mother liquors of the precipitant are prepared, for which substances that can influence the conformation of the molecules can be used; they filter the mother liquor of the precipitator, mix the second part of the protein solutions in equal volumes with the mother liquors of the precipitant, obtaining a collection of crystallisation solutions. Each of the solutions of the named collection is studied by small-angle of X-ray scattering in the temperature range from the temperature at which the molecule of this protein does not become denatured to 0°C with the chosen temperature change step, resulting in the graphs of the small-angle scattering curves, mathematically process these scattering curves, obtaining the distribution of the number of protein subunits and their oligomers in solution, depending on their radius, those crystallization solutions are selected, when processing the small-angle scattering curves from which the formation of the largest number of oligomers in solution was detected, which means finding conditions for crystallisation. If particles that are larger in size than the monomers are not detected in the crystallisation solutions, then step-by-step lower the temperature of the solutions under study to 0°C, at each of the stages of decreasing the temperature of the solution, each of the solutions is studied by small-angle scattering, mathematically processed by these scattering curves, obtaining the distribution of the number of particles in the solution as a function of their radius, those crystallisation solutions are selected, when processing small-angle scattering curves from which the formation of the largest number of oligomers was detected in the solution, the stepwise temperature reduction operation is completed by detecting the greatest number of oligomers, which means finding crystallisation conditions.EFFECT: invention allows to shorten the time for the formation of crystals, as well as to create a direct method for determining the formation of growth units, providing reliable and timely information about the initial stage of crystallisation of the protein.9 cl, 6 dwg
ethod for growing germanium monocrystals // 2626359
FIELD: physics.SUBSTANCE: method involves growing germanium crystals from a melt containing main dopant impurity - stibium and additional one - silicon, in an amount from 1.3⋅1020 cm-3 to 3⋅1020 cm-3 by dissolving silicon rods during the crystal growth.EFFECT: increased temperature stability of optical properties of germanium monocrystals.1 tbl

ethod of producing nanopowder of cobalt ferrite and microreactor to this end // 2625981
FIELD: technological processes.SUBSTANCE: method comprises supplying the primary components - a mixture of solutions of cobalt and iron salts in the ratio corresponding to stoichiometry CoFe2O4, and an alkali solution in proportion to the salts solutions providing acidity of the medium in the range from 7 to 8, corresponding to the conditions of coprecipitation of the components, while the solutions of the primary components are supplied in the form of thin jets with a diameter of 50 to 1000 micron at the speed of 1.5 to 20 m/s colliding in the vertical plane at the angle of 30° to 160°, at the temperature in the range of 20°C to 30°C, and a pressure close to atmospheric pressure. The usage ratio of the primary components is set in such a way that when the jets collide, a liquid fog is formed in which the solutions of the primary components are mixed and engage. The microreactor for the method comprises a housing 1 and nozzles 2 with flow diffusers 3 for supplying primary components 10 and a nozzle 4 for products removal, the microreactor housing 1 is of a cylindrical shape with a conical bottom 5, a cover 6, the nozzles 2 with flow diffusers 3 for supplying primary components 10 are made with the possibility to provide fine adjustment of the jet direction, in the cover 6 coaxially to the housing 1 a nozzle 9 is provided for supplying purging gas, and an outlet nozzle 4 is installed in the bottom 5 to remove purge gas and reaction products. The area of the outlet nozzle 4 is 20-50 times bigger than the total area of all nozzles for supplying primary components. Two or more nozzles 17 may be installed in the cylindrical part of the housing to supply a surface-active substances solution in the form of thin jets with a diameter of 10 to 1000 micron, directed to the liquid fog of the primary components engaging solutions.EFFECT: invention enables to reduce the temperature and pressure necessary to make a synthesis of oxide nanoscale cobalt ferrite particles, to reduce energy costs and ensure continuity of the process with the possibility of its implementation on an industrial scale, to reduce the cost of equipment, to increase yield and selectivity of the process, to provide optimal conditions for rapid reactions via maintenance of stable and effective hydrodynamic conditions for reagents contacting and rapid removal of reaction products.3 cl, 5 dwg, 2 ex
ethod for obtaining modified titanosilicate of pharmacosiderite type // 2625118
FIELD: chemistry.SUBSTANCE: chloride titanium-containing reagent is used in the form of titanium tetrachloride or a mixture of titanium tetrachloride and hydrogen peroxide solution in a molar ratio of 1:(8-16) and added to the silicon-containing reagent as a collective solution of sodium silicate and sodium and potassium hydroxides. The content of the components in the resulting suspension should satisfy the molar ratio TiO2:SiO2:Na2O:K2O:H2O=l:(4,3-6):(6,4-8,7):(0,8-1):(195-700). The suspension is kept in sealed conditions at a temperature of 160-180°C for 8-20 hours to form a solid phase in the form of pharmacosiderite type titanosilicate. The solid phase is separated from the mother liquor, washed with distilled water and dried. Then, the titanosilicate is modified by treatment with a solution containing hydrazine at a concentration of 0.50-1.14 g/l at T:G=1:(100-400) for 0.3-2 hours. The modified titanosilicate is separated, washed with distilled water and dried. The extraction of noble metals in mg per g of the modified product is: gold 260-275, platinum 110-134, palladium 119-141.EFFECT: method allows to obtain a monophasic hydrazinium-modified titanosilicate of the pharmacosiderite type, which has a high sorption ability with respect to noble metals.5 cl, 5 ex
ethod for producing massifs of cobalt nanowires // 2624573
FIELD: chemistry.SUBSTANCE: method involves electrodeposition of cobalt in the pores of the track-etched membranes electrolyte containing⋅ CoSO4⋅7H2O - 300-320 g/l, H3BO3 - 30-40 g/l, at pH 3.5-3.8 and temperature 40-45°C. Electrodeposition is performed using a potential sensor in the form of chloride-argentic reference electrode at a fixed distance between the cathode and the chloride-argentic reference electrode constituting 2-4 mm, and controlled by a constant voltage of 750-900 mV between them.EFFECT: improved homogeneity adjustment wires.4 ex

ethod of obtaining gallium (ii) sulfide // 2623414
FIELD: chemistry.SUBSTANCE: synthesis of GaS was carried out in a closed volume from elemental gallium and sulfur, taken in a stoichiometric ratio, under a hydrogen atmosphere at a pressure of 1300-2600 Pa, while the melt of the gallium had a temperature T(Ga)=1050-1100°C, and the sulfur melt - temperature T(S)=300-350°C.EFFECT: complete flow of the chemical reaction to form a pure single-phase product and with the possibility of scaling the process for industrial applications.1 tbl, 3 dwg
ethod of treating diamond crystals and diamond materials // 2622568
FIELD: chemistry.SUBSTANCE: method of treating diamond crystals and diamond materials by contacting in the presence of hydrogen with metallic template tool, which is capable of dissolving diamond during heating to obtain carbon. Metallic template tool is preliminary saturated with hydrogen for compact and secure storage in the template tool and extraction in the treatment zone to obtain a gaseous compound with a carbon. The treatment is carried out in a protective atmosphere at a temperature of the diamond-carbon solution in the material of the template tool and hydrogen extraction from the template tool.EFFECT: lower hazard level when using gaseous hydrogen in the technical process.6 cl
ethod of obtaining a ceramic precursor for synthesis of leukosaphir // 2622133
FIELD: chemistry.SUBSTANCE: mixture of hydrargillite with 1÷15 wt % of electrocorundum with a grain size of 10-50 mcm is filled with 0.5÷2 wt % of aqueous hydrochloric acid and stirred to form a composition of a homogeneous dispersed phase, the composition is placed in an autoclave in which hydrothermal treatment is carried out at a temperature of 180÷220°C for 4÷26 hours, the resulting mixture of formed and electrocorundum is first heated in a muffle furnace in air at a temperature of no higher than 1200°C until the moisture is completely removed, then transferred to a vacuum oven, heated and maintained at a temperature of 1700 to 1800°C for 1÷2 hours, the resulting ceramic is then cooled to form a precursor.EFFECT: invention makes it possible to produce a ceramic precursor with a high density, which makes it possible in the future to synthesise a qualitative leucosapphire with a low content of mineral impurities.5 ex

ethod of producing monocrystalline sic // 2621767
FIELD: physics.SUBSTANCE: method includes cell growth 1 of crucible 6 with SiC source 12 and docked on the lid 7 of the crucible 6 of seeding plate SiC 11 establishment of cell growth 1 through heat by heater 4, taking into account the insulating ability of thermal screen 3 necessary axial temperature distribution, secured high temperature gradients in the upper and lower zones of growth chambers and low temperature gradients in the zone of maximum heating located between the upper and lower zones, in which the growth chamber at a temperature that ensures that sublimation is a working volume of the crucible, with sublimation of spend in the crucible 6, lid 7 which is docked with the persistence of crucible on a ledge, on the inner surface of the side walls of the crucible, the height H of which exceeds the longitudinal dimension h of the working volume of the crucible and the part of the side walls above the lid 7 of the crucible 6 is located in the upper region of the growth chamber such that the end face 10 of the side wall of the crucible is placed at a temperature of 1000 to 1500°C.EFFECT: enables to increase the output of high-quality monocrystalline ingots of SiC and reduce costs.6 cl, 1 dwg, 1 tbl

ethod of forming coloured decorative coating by anodisation // 2620801
FIELD: chemistry.SUBSTANCE: method of obtaining a decorative coating with a changing colour during visual angle variation consists in the formation of one-dimensional photonic crystal with photonic bandgap in the visible range by anodising the surface of a valve metal or its alloy containing not less than 50% of valve metal at a cyclically varying parameters: current and voltage, wherein each cycle consists of two stages: anodization is carried out at the first stage at current stabilization in the range of 0.1 to 50 mA /cm2 for a time ensuring charge flow from 0.05 to 5 C/cm2; anodization is carried out at the second stage at voltage stabilization, increasing it from the voltage value at the end of the first stage to a value lying in the range from 10 to 200 V, with a decreasing voltage rise rate from 5 V/s to 0 V/s, and is held at this value for a time ensuring charge flow from 0.05 to 5 C/cm2, ensuring more than 1.4 ratio ofmaximal voltage at the second stage to minimal voltage at the first stage, wherein metal surface serves as anode during production of the decorative coating, and inert material is used as cathode, wherein anodisation charge is reduced by 0.01-10% at the first and the second stages at every next anodisation cycle, which amount lies in the range from 20 to 300.EFFECT: invention allows to obtain coloured decorative coatings of high quality using simple and reproducible method characterized by safety and environmental friendliness due to elimination of toxic substances from the technology.9 cl, 10 dwg, 2 tbl, 5 ex
ethod for contactless treatment of diamonds surface // 2620392
FIELD: chemistry.SUBSTANCE: method for contactless treatment of the diamond surface includes heating the diamond surface to a temperature just below the diamond graphitization temperature, with the subsequent contactless impact on a local diamond surface area with a point source of energy by means of which the local temperature of the diamond surface is raised above the graphitization temperature.EFFECT: method allows to obtain a diamond the surface of which will have a nanoscale relief that provides the extension of the diamond application functionalities, while increasing the process efficiency and reducing power consumption for its treatment.3 ex

ethod for producing optical polycrystalline zinc selenide // 2619321
FIELD: physics.SUBSTANCE: method involves growing zinc selenide preforms by evaporating the original powdered or compacted feedstock, condensing the vapors on the heated substrate, for which intermediate vapor condensation is carried out in the container for growing zinc selenide preforms, allowing vapor to pass through the labyrinth formed in the container working space in the form of a plate with projections, whereby the vapor passage to the substrate occurs through the non-linear winding path that facilitates the condensate purification from solid impurities, and further through the carbon graphite filter fixed between graphite rings, followed by re-deposition and transfer of steam to the substrate, wherein the vapor condensation occurrs on the substrate heated to 1030-1070°C, at the rate of 0.2-0.5 mm/h, then the grown zinc selenide preform is cooled and removed from the growth setup, it is placed into the apparatus-gasostat, and hot isostatic pressing is performed at the temperature of 1050-1150°C and the inert gas pressure of 150-200 MPa for 2-3.5 hours.EFFECT: manufacturing a monolithic preform in the form of a circular plate or a spherical concave segment of polycrystalline zinc selenide having increased chemical purity and optical uniformity of a spectral transmittance over the entire grown preform area, extended spectral transparency range with high transmittance in the visible and infrared spectrum areas in the optical parts, manufactured from these preforms.3 cl, 3 dwg, 1 tbl, 1 ex

ethod of manufacturing the epitaxial layer of silicon on a dielectric substrate // 2618279
FIELD: chemistry.SUBSTANCE: method for producing epitaxial layers of monocrystalline silicon of n- and p-type conductivity in a material of dielectric substrates with lattice parameters similar to parameters silicon by chemical vapour phase epitaxy. The substrate material may be used, in particular, leucosapphire (corundum), spinel, diamond, quartz. The method consists in the location of the substrate in the reactor, heating the working surface of the substrate to 900-1000°C, the reaction gas feed stream comprising an inert carrier gas and monosilane silicon capacity to form an initial continuous layer on the working surface of the substrate, adding to the flow of the reaction gas a halogen-containing reactant stream and forming an epitaxial silicon layer of desired thickness. Starting solid silicon layer is increased at a rate of 3000 E/min to 6000 E/min. After forming the layer on the working surface of the substrate of the reaction gas flow rate is reduced, reducing the growth rate at 500-2000 E/min. To the flow of the reaction, the gas stream of saturated vapour of silicon halide or halosilane gas is added, whose flow rate is set so that the growth rate of the silicon layer returned to the values of 3000-6000 E/min.EFFECT: obtaining high quality silicon layer and reducing the cost of the manufacturing process.3 dwg, 1 ex

Optical medium based on crystal of halide rubidium-yttrium rby2cl7, containing monovalent bismuth impurity ions, capable of broadband photoluminescence in near ir-range, and its manufacturing method // 2618276
FIELD: physics.SUBSTANCE: optical medium is proposed based on the halide crystal containing low-valency bismuth ions as the only optically active center, capable of broadband luminescence in the near IR-range, which is a crystal phase of rubidium chloride-yttrium RbY2Cl7containing isomorphic admixture of monovalent bismuth ions Bi+ in the amount of 0.1 to 1 at. %. The optical medium fluoresces in the range of 800-1100 nm, when excited by radiation with the wavelengths in the range of 570-780 nm. The process for producing the optical medium includes preparing a batch by mixing RbCl, YCl3 and BiCl3 in the molar ratio of 1:2:0.003-0.03, adding metal bismuth to the batch at the molar ratio of BiMe/BiCl3=1, placing the mixture in the quartz container in a vacuum into the vertical oven of Bridgman-Stockbarger, where the temperature in the hot zone is 620-630°C, in the cold zone - 480-500°C, and the movement speed of the container from the hot zone to the cold one is 0.2-2 mm/h to form a single-crystal sample of the optical medium. The obtained optical medium has a stable luminescence in the near IR-range, which allows its use as the active medium for the broadband amplifiers and lasers.EFFECT: method for producing a chloride crystal is fairly simple and technological and allows to grow high-quality crystals of the required size.3 cl, 3 dwg, 3 ex
 
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