Method for obtaining doped diamond monocrystal

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

 



 

Same patents:

FIELD: physics.

SUBSTANCE: this method comprises application of doping element film on the surface of specimen of zinc chalcogenides or their solid solutions. Said doping element can be one or several elements of the following series: chromium, cobalt, iron. Then, diffusion annealing is performed at 90-200 MPa and 1100°C-1350°C.

EFFECT: bulky specimens of high quality.

2 cl, 2 dwg, 1 tbl, 1 ex

FIELD: jewelry industry; optics.

SUBSTANCE: proposed method is used for coloring fianites (man-made diamonds) in green, blue and brownish-yellow colors; proposed method may be also used in optics for production of colored light filters withstanding temperatures above 1000°C. Proposed method includes preliminary application of cobalt on fianite surface to be colored and at least one metal whose oxide is liable to spinelle-forming with oxide of bivalent cobalt, iron and/or aluminum, for example. Then material is subjected to heat treatment in oxygen-containing atmosphere at temperature above 1000°C but not exceeding the fianite melting point. The procedure is continued for no less than 3 h. Coat is applied by thermal spraying of metals in vacuum. Said metals may be applied in turn and simultaneously. For obtaining bluish-green color of fianite, cobalt and aluminum are applied at atomic ratio of 1:1 to 1:2. For obtaining yellowish-green color, cobalt, aluminum and iron are applied at atomic ratio of 1:1 :0.1-0.2. For obtaining yellowish-brown color, cobalt and iron are applied at ratio of 1:1 to 1:2.

EFFECT: enhanced resistance to high temperature and chemical action.

7 cl, 11 ex

FIELD: jewelry technology; manufacture of jewelry colored inserts.

SUBSTANCE: synthetic corundum contains alumina, color-forming additives and binder-paraffin. Required color is obtained as follows: for obtaining black color molybdenum oxide is added to alumina in the amount of 0.03%; for obtaining gray color, tungsten oxide is added to alumina in the amount of 0.01%; for obtaining blue color, neodymium oxide is added in the amount of 0.01%; for obtaining pink color, erbium oxide is added to alumina in the amount of 0.01%; for obtaining red color, chromium oxide is added in the amount of 0.05%. Proposed method of manufacture of jewelry articles includes molding in casting machines at a pressure of 4 atm and roasting; first roasting cycle is performed in continuous furnaces for burning-out the binder and is continued for 90 h at temperature of 1150 C; second roasting cycle is performed in batch furnaces at temperature of 1750 C and is continued for 170 h for forming and sintering of microcrystals making translucent crock at density of 4 g/cu cm and hardness of 9 according to Mohs hardness scale; then polishing is performed with the aid of diamond materials. Articles thus made have high-quality miniature texture at hardness which is disadvantage in relation to diamond only.

EFFECT: high quality of articles; enhanced hardness of articles.

7 cl

The invention relates to the fine processing technology of natural and synthetic gemstones, namely technology colorless color inserts of gem-based oxide materials

The invention relates to the field of quantum electronics and can be used in the manufacture of laser rods of complicated oxide high-temperature material

FIELD: chemistry.

SUBSTANCE: invention relates to a method of controlling concentration and uniformity of distribution of a dopant in synthetic CVD diamond material used in electronic devices and sensors. The diamond material is obtained in a microwave plasma reactor, having a plasma chamber 102 in which there is one or more substrate regions of a growth surface 105, on top of which the diamond material is deposited, a gas stream system 112 for feeding process gases into the plasma chamber 102 and a system 122 for removing the process gases therefrom. Microwave radiation is transmitted from a microwave generator 106 into the plasma chamber 102 through a microwave link 110 in order to generate plasma above the region of the growth surface 105 or below the region of the growth surface if the microwave plasma reactor is in an inverted configuration with the process gases flowing upwards. The gas stream system 112 includes a gas inlet, having one or more gas inlet pipes 124 located opposite the region of the growth surface 105 and configured to inject process gases towards the region of the growth surface 105, wherein the process gases are injected into the plasma chamber 102 through one or each gas inlet pipe 124 with a Reynolds number in the range of 1-100, integrally formed in the metal wall of the plasma chamber 102 located opposite the region of the growth surface 105. The plasma chamber 102 is configured to support standing microwave modes TM011. The configuration of the microwave link 110 comprises a microwave window 119 for transmitting microwave radiation from the microwave generator 106 into the plasma chamber 102, which is located at the opposite end of the plasma chamber 102 relative to the region of the growth surface 105 and made in the form of an annular dielectric window.

EFFECT: invention enables to achieve a homogeneous chemical composition of diamond material grown in a single growth cycle while maintaining uniform plasma with a large area with very high growth rates and enables to achieve a high degree of controlling the level and distribution of defects and dopants in a diamond film without impurities and damages to the walls and the microwave window of a plasma chamber which can support compact standing microwave mode TM011.

5 cl, 17 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to manufacturing of polycrystalline materials, which can be used, preferentially for producing drilling and dressing tools. A polycrystalline diamond composite with a dispersion-strengthened additive contains a refractory metal coating 0.02-0.15 mm thick containing diamond powder and metals with the metal presented by nickel, cobalt, whereas the dispersion-strengthened additive is tungsten carbide nanopowder in the following proportions, wt %: diamond - 85-90, nickel - 7-9, cobalt - 2-4, tungsten carbide nanopowder - 0.1-3.0.

EFFECT: technical effect consists in increasing the strength and wear resistance of the sintered composite, and selecting the high-melting coating ensures the reliable attachment of the material in the drilling tool.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to production of monocrystalline diamond material by chemical vapour deposition (CVD), which is used in optical, mechanical, fluorescent and/or electronic devices. A diamond layer contains a mesh of nonparallel intercrossing dislocations as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique, wherein the layer has thickness equal to or greater than 1 mcm; the mesh of nonparallel dislocations stretches across a volume which is at least 30% of the total volume of the diamond layer, and wherein the mesh of nonparallel dislocations contains a first set of dislocations propagating in a first direction through the diamond layer, and a second set of dislocations propagating in a second direction through the diamond layer, wherein the angle between the first and second directions is in the range of 40° to 100°, as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique.

EFFECT: invention enables to control the type and/or direction of dislocations in a diamond material without affecting optical and/or electronic properties of devices based on said material and optimise said properties for a specific application.

12 cl, 8 dwg, 2 tbl, 3 ex

FIELD: nanotechnology.

SUBSTANCE: invention relates to nanotechnology and can be used for labelling molecules, quantum information processing, magnetometry, and synthesis of diamond by chemical vapour deposition. Crystalline diamond powder with a maximum particle size of 2 microns to 1 mm is ground by the nitrogen jet for 1-5 hours with the grinding pressure of 500 kPa to obtain the fine powder which is then milled in a planetary mill with balls of tungsten carbide. The resulting nano-ground powder is autoclaved with the mixture of hydrofluoric acid and nitric acid at a temperature of 100-200°C. The fluorescent cubic nanocrystals of diamond of predominantly circular shape are recovered by centrifugation, with a maximum size of not more than 100 nm, comprising up to 2,000 ppm alloy addition, such as nitrogen, and up to 50 ppm of impurities. The surface of the diamond nanocrystal comprises a layer of amorphous carbon.

EFFECT: obtaining diamond nanocrystals.

15 cl, 8 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing coloured diamond materials, which can be applied as precious stones or cutting instruments. Method includes stages of growing monocrystalline diamond material in accordance with CVD-technology, with diamond material having concentration of single substituting nitrogen atoms [Ns0] less than 1 ppm; initial CVD-diamond material is colourless, or, in case it is not colourless, then, according to colour gradation brown or yellow, and if it is brown according to colour gradation, then it has level G (brown) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and if it is yellow according to colour gradation, it has level T (yellow) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and irradiation of initial CVD-diamond by electrons to introduce isolated vacancies into diamond material in such a way that product of the total concentration of vacancies × way length [Vt]×L, in irradiated diamond material at said stage or after additional processing after irradiation, including annealing irradiated diamond material at temperature at least 300°C and not higher than 600°C, constitutes at least 0.072 ppm cm and not more than 0.36 ppm cm.

EFFECT: diamond material becomes fancy light-blue or fancy light greenish blue in colour.

21 cl, 4 dwg, 3 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in obtaining jewellery diamonds. method of introduction of NV-centres in monocrystalline CVD-diamond material includes the following stages: irradiation of CVD-diamond material, containing single substituting nitrogen, for introduction of isolated vacancies in concentration at least 0.05 ppm and at most 1 ppm; annealing irradiated diamond to form NV-centres from at least some of defects of single substituting nitrogen and introduced isolated vacancies.

EFFECT: invention makes it possible to obtain pink CVD-diamond material and CVD-diamond material with spintronic properties.

18 cl, 12 tbl, 7 dwg

Diamond material // 2537857

FIELD: chemistry.

SUBSTANCE: inventions can be used in chemical and jewellery industry. Nitrogen-doped diamond material, obtained in accordance with CVD technology, or representing monocrystal or precious stone, demonstrates difference of absorptive characteristics after exposure to radiation with energy of at least 5.5 eV, in particular UV radiation, and thermal processing at temperature 798 K. Defects into diamond material are introduced by its irradiation by electrons, neutrons or gamma-photons. After irradiation, difference in absorptive characteristics decreases.

EFFECT: irradiated diamond material has absorption coefficient lower than 0,01 cm-1 at 570 nm and is capable of changing its colour.

18 cl, 7 dwg, 11 tbl, 15 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of alloys diamonds to be used in electronics and instrument making s well as jewellery stones. Alloyed diamond is produced by chemical deposition of gas phase on substrate in reaction chamber 2. Alloying solid-state component 7 is placed in alloying chamber 3. The latter has at least three connection flanges. Two of them are designed to connect alloying chamber 3 with working gas feed line 1 while third flange allows passage of pulsed laser radiation 8 via translucent window 5 into alloying chamber 3 for sputter of alloying component 7. Note here that alloying component concentration in diamond is adjusted by varying the laser parameters: laser diode pump current, laser pulse frequency and distance from laser radiation focus to alloying component surface. Working gas can be composed of the mix of hydrogen and methane at the ratio of 98:2% to 90:10%. Additionally, oxygen can be added thereto.

EFFECT: precise alloying in the wide range of concentrations (1014 atom/cm3 to 9×1019 atom/cm3) of boron, sulphur and silicon.

3 cl, 1 dwg, 4 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: ions of carbon with opposite charges interact with each other for 20-30 hours at a temperature of 850-950 °C in a high frequency electro-field in the range of frequencies of 40-80 kHz in the presence of iron as a catalyst. The process is carried out in a melt of salts, containing, wt %: SiC - 7.5-11.0; Na2CO3 or K2CO3 - 89.0-92.5. Applied is granulated iron, which has a size of granules 1-3 mm, in a quantity of 5-10% from the melt weight.

EFFECT: invention makes it possible to simplify the process of the diamond synthesis and its instrumentation, eliminate harmful and dangerous conditions.

1 tbl, 1 ex

Pcd diamond // 2522028

FIELD: process engineering.

SUBSTANCE: invention relates to PCD diamond to be used in production of water-jet ejectors, engraving cutters for intaglio, scribers, diamond cutters and scribing rollers. PCD diamond is produced by conversion and sintering of carbon material of graphite-like laminar structure at superhigh pressure of up to 12-25 GPa and 1800-2600°C without addition of sintering additive of catalyst. Note here that sintered diamond grains that make this PCD diamond feature size over 50 nm and less than 2500 nm and purity of 99% or higher. Diamond features grain diameter D90 making (grain mean size plus grain mean size × 0.9) or less and hardness of 100 GPa or higher.

EFFECT: diamond features laminar or fine-layer structure, ruled out uneven wear, decreased abrasion.

15 cl, 5 tbl, 5 ex

Reforming catalyst // 2558150

FIELD: chemistry.

SUBSTANCE: invention relates to method of reforming with application of catalyst. Described is method of reforming hydrocarbons with water vapour, including contact of supplied gas in reactor of catalytic partial oxidation or installation for autothermal reforming. Reactor operates at temperature 800-1600°C and pressure of 20-100 bar. Egg shell type catalyst, consisting of active compound in form of alloy of nickel and one metal from iridium and ruthenium, on supporter, containing aluminium oxide, zirconium dioxide, magnesium oxide, titanium dioxide or their combinations. Catalyst has cylindrical shape and has one or several through holes, where distance from centre to external catalyst surface constitutes from 10 to 40 mm, catalyst height constitutes from 10 to 40 mm, with diameter of one or several through holes constituting from 3 to 30 mm. At least 90 wt % of iridium or ruthenium in catalyst are located in external envelope which has depth up to 10% of external catalyst surface or to 10% of periphery of one or several through holes of catalyst.

EFFECT: realisation of method of catalytic partial oxidation or autothermal reforming at reduced drop of pressure in catalyst layer without reduction of catalyst activity.

12 cl, 5 dwg, 2 tbl, 5 ex

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of petrochemistry and more specifically to a method of producing synthesis gas which is used as the feedstock, for example, for the synthesis of methanol, dimethyl ether, hydrocarbons by Fischer-Tropsch method. The method of producing synthesis gas comprises oxidative conversion of methane-containing gas at a temperature more than 650°C in through-flow riser, using as oxidant the microspherical or crushed catalyst based on metal oxides, capable of multiple redox transitions, at that the catalyst is continuously passed through the riser upwards in the methane-containing gas flow with a residence time of the feedstock in the reaction zone of 0.1-10 s, separating the catalyst passing from the reactor from the product and regeneration of the catalyst by oxidation with carbon dioxide in the regenerator from which the regenerated catalyst enters the reactor. The oxidative conversion of methane-containing feedstock and regeneration of regenerated catalyst is carried out simultaneously and continuously.

EFFECT: invention enables to improve the removal rate of the product, to reduce energy consumptions for transportation of oxygen-containing agent, to reduce the risk of explosion and ignition, as well as to adjust the composition of the synthesis gas.

7 cl, 1 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in obtaining hydrogen from reagents, including liquid hydrocarbons, gaseous hydrocarbons and/or oxygen-containing compounds, including those, obtained from biomass, and their mixture. In order to obtain hydrogen used are: section of reagents heating; section of catalytic partial oxidation with short contact time, in which synthesis-gas is obtained; section of heat recuperation; section of converting carbon monoxide, present in synthesis-gas, into carbon dioxide by reaction of water gas conversion; section of said carbon dioxide removal; section of condensate cooling and removal.

EFFECT: invention makes it possible to obtain H2 and CO2 of high purity and purge gas with average heat-generating ability, which can be used in combustion processed and/or introduced into installation fuel supply system.

17 cl, 2 dwg, 5 tbl, 5 ex

Up!