Multi-layer tape nanostructure composite based on superconducting niobium-titanium alloy
FIELD: physics; conductors.
SUBSTANCE: invention relates to making composite superconductors with improved current-carrying capacity and can be used, particularly, for making superconducting magnet windings. According to the invention, the multi-layer tape nanostructure composite based on a superconducting niobium-titanium alloy contains alternating layers of niobium and niobium alloy-(25-45) wt % titanium, with layer thickness of not more than 50 nm. The thickness of each niobium layer is 50-70% of the alloy layer thickness.
EFFECT: obtaining a composite with critical current density of 58000 A/cm2 in a magnetic field with flux density of 6 T.
2 cl, 3 tbl
The invention relates to the field of creation of new nanostructured multilayer composite superconductors on the basis of niobium alloys with improved current-carrying abilities and can be used, in particular, to create windings of superconducting magnets.
Currently great interest are materials containing alloys of Nb-Ti and Nb-Zr. Multilayer planar nanostructured composites based on such alloys are promising for the creation of superconducting materials with high current-carrying capacity. The presence of the tape superconductor planar, parallel layers, the thickness is 10-100 nm, and is thus comparable with the coherence length of the superconductor, allows you to use the effect of a long, flat surface that is parallel to the external magnetic field, pinning (fixing) of Abrikosov vortices and, therefore, the value of the critical current density.
Known multilayer composite [patent US 5230748, H01L 39/24, July 19, 1991], in which the superconducting layers of alloys of the system Nb-Ti-Zr-V-Hf-Ta at the final stage of manufacture of a superconductor is produced by diffusion annealing of the composite of alternating layers of these metals or their alloys, and the thickness of the normal and superconducting layers, formed during the annealing must be less than 1000 nm.
However, for diffuzionnogo annealing of the composite leads to the complexity of the process.
Known also two patents related to obtaining flat superconductors, in which the superconducting layers are flat across the entire width of the tape. In the first [US 4729801, H01L 39/24, 1986] proposed to apply a superconducting connection on a moving flat substrate by electron beam deposition, in the second [JP 1212747, B22D 11/01, 1988] - the rough copper substrate through a molten superconductor.
However, although both these methods allow to obtain thin layers of superconductor and to achieve high critical current density, but they do not provide a multilayer conductors capable of carrying large total shock, because this requires that these layers were as much as possible.
Famous adopted for the prototype, multilayer tape nanostructured composite-based alloy niobium-titanium containing alternating layers of niobium and niobium alloy, titanium, consisting of 64000 layers of niobium and an alloy Nb-50 wt.% Ti with an average thickness of each layer of 2.5 nm [Miechow, Vperiod, Vigneau, Wensveen, Isabekova "Anisotropy density of the superconducting critical current in layered nanostructured composites containing layers of the alloy Nb-50% Ti" // "Science", 2008, №6, p.35-38]. Flat layers of superconducting alloy Nb-50 wt.% Ti, the thickness of which is equal to 2.5 nm, comparable with the coherence length of the superconductor, which would allow auth to use the effect of a long, flat border between the layer of niobium and a layer of the alloy Nb-50 wt.% Ti, parallel external magnetic field, the pinning of Abrikosov vortices and, therefore, the value of the critical current density.
However, the critical current density in the above-described superconducting composite does not exceed 4500 A/cm2in a magnetic field of 6 Tesla.
The present invention solves the problem of creating nanostructured composite with significantly higher critical current density, capable of carrying a large total shock.
This object is achieved by the proposed structure of the multilayer tape nanostructured composite based on superconducting alloy of niobium-titanium containing alternating layers of niobium and niobium alloy-titanium, the novelty of which consists in the fact that as the alloy Nb-Ti it contains the alloy Nb-(25-45) wt.% Ti, the thickness of the layer is not more than 50 nm. The thickness of each layer of niobium is 50-70% of the thickness of the layer of alloy.
To stabilize the superconductor outer surfaces of nanostructured composite covered with a layer of copper.
The technical result of the invention is to obtain a superconducting material, the critical current density which is 58,000 A/cm2at 6 Tesla at the optimum thicknesses of the layers constituting the composite.
Table 1 shows the indices of the critical current density at 6 Tesla announced aemula multilayer nanostructured composite depending on the titanium content in the alloy. The thickness of the alloy layer was ~12 nm; the thickness of the layer of niobium - ~8 nm.
Table 2 shows the indices of the critical current density at 6 Tesla claimed multilayer nanostructured composite depending on the thickness of the layer of alloy. The thickness of the layer of niobium was ~67% of the layer of the alloy Nb-30 wt.% Ti.
Table 3 shows the performance of the critical current density at 6 Tesla claimed multilayer nanostructured composite depending on the thickness of the layer of niobium. The thickness of the layer of the alloy Nb-30 wt.% Ti was ~12 nm.
The following examples illustrate, but not limit the invention.
Samples of multilayer tape nanostructured composite in the form of a tape width of 30-40 mm and a thickness of 0.15 mm was obtained, as in the previously described method [Karpov M.I., Grandchildren, V.I., Volkov KG, Bear, NV, I.I. Khodos, Abrosimova G. "the features of the vacuum rolling as a method of producing a multilayer composites with nanometric thicknesses of layers, materials Science, 2004, No. 1, p.48-53] by the method of high-rolling. Each cycle consisted of three successive operations: build the package from source plates, vacuum hot rolling, cold rolling. In the first cycle of the original plates were components of the composite, in the second and subsequent cycles plates obtained in the previous cycle.
First with the Orc composite Nb b-30 wt.% Ti) consisted of 16 niobium foils and 15 foils alloy Nb-30 wt.% Ti. The thickness of the source foils alloy was equal to 0.3 mm, the thickness of each foil niobium was 0.2 mm or 66.7% of the thickness of the alloy foil.
Vacuum rolling in each cycle was performed for 2 passes heated samples up to 900°C and the total compression of 50%. Cold rolling in each cycle was finished to a thickness of 0.3 mm In the third cycle were rolling to the final thickness of 0.15 mm was obtained a composite consisting of 28830 layers of niobium and an alloy Nb-30 wt.% Ti. The estimated thickness of the alloy layers was equal to 12 nm, the calculated thickness of each layer of niobium was equal to 8 nm, which accounted for 66.7% of the thickness of the layer of alloy. According to scanning electron microscopy estimated thickness of the layers satisfactorily coincided with the measured average thickness of the layers.
After the last rolling all the samples were annealed at 400°C for 3 hours for separation of dispersed particles of α-phase in the alloy layers Nb-30 wt.% Ti.
The critical current was measured at the liquid helium temperature in an external magnetic field up to 7 Tesla with its two orientations: parallel to the plane of the obtained composite (nanolaminate) and perpendicular to the transport current (in this case, the Lorentz force is directed perpendicular to the plane of nanolaminate and is pinning on the interlayer surface)perpendicular to the plane of nanolaminate, and the transport current (in this case, the pinning is and interlayer surface is absent). The critical current density was determined by the ratio of total transport current to the entire cross-sectional area of the composite.
The critical current density of the obtained composite is 58,000 A/cm2in a magnetic field of 6 Tesla.
Same as in example 1, except that before the last rolling of the Assembly of the package is placed between two plates of copper.
Thus obtained composite acquires stabilizing properties.
Same as in example 1, except that the content of Ti in the alloy Nb-Ti was varied from 20 to 50 wt.%. The thickness of the alloy layer was ~12 nm; the thickness of the layer of niobium - ~8 nm. Indicators of critical current density at 6 Tesla obtained multilayer tape nanostructured composite are shown in table 1.
As can be seen from the table, by reducing the content of Ti in the alloy Nb-Ti below 25 wt.% and with increasing Ti content in the alloy above 45 wt.% it was observed a strong decrease of the critical current density
Same as in example 1, except that the layer thickness of the alloy Nb-30 wt.% Ti in the composite was varied from 2.5 to 55 nm. The thickness of the layer of niobium was ~67% of the layer of the alloy Nb-30 wt.% Ti. Indicators of critical current density with 6 T of the obtained multilayer nanostructured composite are shown in table 2.
As the table shows, with increasing layer thickness of the alloy Nb-30 wt.% Ti composite above 50 nm was observed for the to maintain the lowering of the critical current density.
Same as in example 1, except that the thickness of the Nb layer in the composite ranged from 45-75% of the thickness of the layer of alloy. The thickness of the layer of the alloy Nb-30 wt.% Ti was ~12 nm. Indicators of critical current density at 6 Tesla obtained multilayer nanostructured composite are shown in table 3.
As can be seen from the table, by reducing the thickness of the Nb layer in the composite below 50 and above 70% of the thickness of the layer of the alloy was observed a decrease of the critical current density.
The above examples confirm the reception of the multilayered nanostructure composite-based alloy niobium-titanium high at the present stage of the prior art indicator of the critical current density, equal 58000 A/cm2in a magnetic field of 6 Tesla.
|№ p/p||The content of Ti in the alloy Nb-Ti, wt.%||Indicators of critical current density at 6 T,|
|№ p/p||The thickness of the layer of the alloy Nb-30 wt.% Ti composite, nm||Indicators of critical current density at 6 T, A/cm2|
|№ p/p||The thickness of the Nb layer in the composite % of the thickness of the alloy Nb-30 wt.% Ti||Indicators of critical current density at 6 T, A/cm2|
1. Multilayer tape nanostructured composite based on superconducting alloy of niobium-titanium containing alternating layers of niobium and niobium alloy, titanium, characterized in that as the alloy niobium-titanium it contains alloy niobium - (25-45) wt.% titanium, the thickness of the layer is not more than 50 nm, the thickness of each layer of niobium is 50-70% of the thickness of the layer of alloy.
2. Multilayer tape nanostructured composite according to claim 1, characterized in that its outer surface covered with a layer of copper.
FIELD: electrical engineering.
SUBSTANCE: in a line for transmitting and distributing direct current a power cable line is provided, which makes easier supply of electricity to various devices used for operation of that line. The power cable line comprises power cables (1lg, 1r, 1p, 1m, 1n), which transmit and distribute direct current, a unit (2) for superimposing an alternating current component on these cables, and an electricity tap off unit (3), meant for tapping off power of the superimposed alternating current component from this cable. Unit (2) superimposes the alternating current component on the power cable, and electrical energy of the alternating current is transmitted together with electrical energy of direct current on the power cable. The tap off unit (3), located at a certain section of the cable, taps off this alternating current component and transmits it to different devices.
EFFECT: invention allows for designing a cable, which makes easier tapping off electrical energy during transmission of direct current.
4 cl, 13 dwg
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering, particularly to super-conducting cable capable to absorb thermal compression of super-conducting wire. Super-conducting cable comprises a super-conducting wire coiled to form a super-conducting layer (layer-conductor) (13), reverse conductor (17), a layer of strain relaxation (12), an insulating layer or an outer strain relation layer (16) arranged on the super-conducting layer outer side and cable carcass, (11) arranged on the strain relaxation layer inner side.
EFFECT: superconducting layer compression absorption by cooling superconducting wire with coolant.
9 cl, 4 dwg, 1 tbl
FIELD: electrical engineering.
SUBSTANCE: invention is related to the field of electric engineering, in particular, to superconductive cable, which contains frame (2), layer (3) of superconductive conductor formed around external periphery of frame (2), insulating layer (4) formed around external periphery of conductor layer (3), screening layer (6) formed around external periphery of insulating layer (4), and normally-conductive metal layer (5) formed between insulating layer (4) and screening layer (6). Normally-conductive metal layer (5) is located inside the screening layer (6), has inductivity higher than of screening layer (6).
EFFECT: provides suppression of temperature rise in case of accidents, such as short circuits, and reduction of AC losses in normal mode of operation, since high currents flow through screening layer.
10 cl, 3 dwg
SUBSTANCE: thermo stabilised superconductors are implemented in the shape of matrix from metal or alloy, containing fibers of superconducting material and combination of rare-earth metals with extremely high heat capacity at low temperatures. At that superconductor contains at least two metallic tubes of unconditioned cross-section filled by combination of rare-earth metals and distance between tubes is not less then two tube linear dimensions. Superconductor has external envelope made from metal with high conducting properties. Tubes with combination of rare-earth metals can be distributed either by section of conductor as in matrix or by envelope.
EFFECT: extension of superconductor capabilities by means of increasing of its heat-absorbing abilities.
FIELD: chemistry; electric wire.
SUBSTANCE: material in the form of oxide superconducting wire, which comprises oxide superconducting part and metal coating thereon, distinguishing itself by the fact that the above metal coating material during stress-strain relationship test features relative rupture strain of 30% or more.
EFFECT: material in the form of superconducting wire features high critical current density and is less susceptible to vertical cracking or breaking during manufacture.
14 cl, 3 dwg, 1 tbl, 10 ex
FIELD: applied superconductivity.
SUBSTANCE: proposed composite superconductor that can be used to manufacture superconductors for superconducting windings suffering heavy mechanical loads (at operating pressure across conductor higher than 100 MPa) as well as for superconducting windings and devices operating under variable conditions, such as superconducting inductive energy storage devices, dipole and quadrupole magnets for charged particle accelerators, has superconducting material fibers, matrix of high-conductivity metal, such as copper and rare-earth intermetallide possessing high thermal capacity at low temperatures. Composite superconductor is provided with metal sheath accommodating rare-earth intermetallide; mentioned wires and conductor are welded together. Metal sheath can be made in the form of hollow cylindrical conductor or flat strip with hollow interlayer, their hollow spaces being designed to dispose rare-earth intermetallide. Composite superconductor is made in the form of a few multiple-fiber composite superconducting wires twisted around hollow cylindrical conductor accommodating rare-earth intermetallide. Composite superconductor can be made in the form of flattened single-lay strand of several multiple-fiber composite superconducting wires and several hollow cylindrical conductors of same diameter accommodating intermetallide which alternately vary within strand. Rectangular-section conductor is made of high-conductivity metal and has longitudinal groove.
EFFECT: enlarged functional capabilities.
7 cl, 8 dwg
SUBSTANCE: invention refers to fire-heat-shielding coating and can be implemented in rocket engineering at applicating coating on interior surface of nozzle of rocket engine. The installation for coating application consists of a high pressure chamber for electric-arc sputtering of graphite containing electrodes, of a shaft and of anodes secured on the shaft by means of telescopic pistons. Anodes consist of one or more sectors made out of mixture of carbon and metal-catalyst capable to encapsulation of carbon nano-particles inwards. Treated nozzle is used as cathode. Coating is made in form of nano-structural material and contains a porous frame formed with carbon nano-tubes or nano-cones, or fullerenes and atoms of metal or metals with various physic-chemical properties encapsulated in them.
EFFECT: decreased weight of coating at maintaining indicators of heat efficiency and facilitation of automation of coating application process.
2 cl, 5 dwg
SUBSTANCE: activation of chalcogen and dichalcogenide is implemented beforehand in alkali containing hydrazine-hydrate at temperature 70-80oC at ratio alkali/chalcogen equal to 2.3-2.5:1 for sulphur and selenium 6-8:1 for tellurium and at ratio alkali/dichalcogenide equal to equal to 2.5-3.0:1. Alkali is potassium or sodium hydroxide, organic dichalcogenide is compound of general formula R2Y2 whereat R - C6H5, C6H5CH2, C2H5, C4H9, HOCH2CH2, (HOCH2)2CH, CH2=CHCH2, C8H17. Nanoparticles are obtained by interreaction of metal salt with elemental chalcogen and in the meantime with organic dichalcogenide being the source of ligands - nanoparticles stabilisators at temperature 40-60oC. The resultant chalcogenide semicondactive nanoparticles have the general formula MenYm(YR)2(n-m) whereat Me - Zn, Cd, Hg, Y - S, Se, Te, n=10-30, m=8-24, R is organic radical.
EFFECT: simple nanoparticles obtaining and high yield of the product.
2 cl, 1 tbl
SUBSTANCE: disclosed installation consists of casting tank with two rows of ports and fissured moving grate and of crystalliser with two pairs of vertical walls. The first pair of walls of the crystalliser is made in form of heat pipes with heating and cooling devices; this pair is designed to perform reciprocal motions, while the second pair is designed to perform rotating motions and converge; it has expanded upper and vertical lower sections. In the middle part of the casting tank there is located an additional tank with a stop and an immersing casting cup. Metal in amorphous state comes to expanded sections of crystalliser walls from the casting tank overcooled below temperature of crystallisation. Simultaneously overheated metal comes from the additional tank to the centre of the crystalliser. Separate supply of the same metal with different temperature into the crystalliser creates conditions for producing nano-crystal structure of the billet.
EFFECT: increased efficiency of production of nano-crystallised billets.
2 cl, 2 dwg
SUBSTANCE: method of nanohybrid sopbent for organic substances separation is claimed. The said method includes obtaining of the metal nanoparticles adsorbed on the carrier by the way of said particles mixing with carrier, following filtration and washing and their modification with sulphur-containing organic substances (thiols and bisulphides). The obtained sopbent contains the carrier with adsorbed metal nanoparticles and ligands based on sulphur-containing organic substances covalently fixed on the surface.
EFFECT: method provides reproducible obtaining of stable sorbents allowing separation of the wide range of organic substances; enhancing of the obtained sorbents selectivity.
4 cl, 4 dwg, 7 ex
SUBSTANCE: invention relates to devices for carbon nanotubes production. Device contains reaction furnace with unit for supplying and introducing of ethanol vapours, holder of padding with padding, which has catalytic surface, and heating element. Inside of reaction furnace placed is reaction chamber, which contains separable part, joint with drive of axial movement. Unit of ethanol vapours supply contains evaporating cell with ethanol, joint with ethanol vapours input. Heating element is placed inside reaction chamber in padding zone. Device is supplied with generator of particle flow, placed in reaction chamber, and made in form of at least one conductive net, connected to source of alternating or/and source of continued voltage. At least one conductive net is made of catalytic material. Reaction chamber is made of quartz ceramics. In evaporating cell heater and ethanol temperature measuring instrument are placed. Inlet of ethanol vapours is made of conductive material, and is connected to source of alternating or/and source of continued voltage. Inlet of ethanol vapours is made in form of two pipes, which are coaxially placed one in the other with ability to move relative each other.
EFFECT: increasing nanotubes quality and device reliability.
6 cl, 1 dwg
SUBSTANCE: invention relates to powder metallurgy, in particular to obtaining samples to determine the best composition of a hard alloy. A layer of nanoparticles of tungsten carbide is laid on the layer of hard-alloyed mixture in the press mould or a layer of nanoparticles of tungsten carbide is placed between the layers of hard-alloyed mixture which is followed by pressing of the both layers. After sintering the mechanical and physical properties as well as structural parametres are evaluated by performing layer-by-layer measurements along the concentration axis including transition zones formed by diffusion of the nanoparticles into the hard alloy.
EFFECT: improved composition of the hard alloy with enhanced mechanical-and-physical properties and a low porosity.
4 dwg, 1 tbl
FIELD: physics; semiconductors.
SUBSTANCE: invention concerns processes of chemical machining of slices and can be used for creation of silicon bodies with nanosized structure, applicable as emitters of ions in analytical devices and for creation of light emitting devices. Essence of the invention consists in the reception method of nanostructure silicon base plates by processing of siliceous substances with a gas-vapor mix containing hydrofluoric acid and an oxidising substance, as an oxidising substance halogen or its mix with a oxygen-containing oxidising reagent taken in number of not less than 1.0% is used. Iodine can be used as halogen, and in quality of an oxygen-containing oxidising reagent - a reagent chosen from the group: ozone, peroxide, sulfuric acid, nitric oxide. The invention allows to Iodine can be used as halogen, and in quality of an oxygen-containing oxidising reagent - a reagent chosen from the group: ozone, peroxide, sulfuric acid, nitric oxide.
EFFECT: obtaining of base plates keeping stability of physical and chemical properties of a surface at long storage in natural conditions and providing high uniformity of physical and chemical properties of a surface and, accordingly, higher reproducibility of the analysis at use of such base plates.
8 cl, 6 dwg, 1 tbl
SUBSTANCE: invention relates to microstructural technologies, namely to nanotechnology, in particular, to method of obtaining fibrous carbon nanomaterials which consist from carbon nano-tubes, by method of precipitation from gas phase. Reactor is filled with inert gas and its central part is heated. Then reaction mixture containing carbon source and ferrocene catalyst source is injected, which under impact of temperature turns into vapour. Vapour is kept in hot zone by ascending inert gas flow, source of padding for precipitation of catalyst nanoparticles and growth of carbon nano-tubes being introduced into reaction mixture. As padding source used are complexes of macrocyclic polyesters with salts of metals selected from line Ca, Ba, Sr, Y, Ce, which have temperature of decomposition lower than catalyst source, and serve as continuous source of padding.
EFFECT: synthesis of carbon nano-tubes is performed continuously, which results in increase of carbon nano-tubes output.
1 dwg, 3 ex
SUBSTANCE: invention relates to nanotechnology and nanomaterials and can be used at receiving of inorganic and organic-inorganic fine-grained and nano-structured metallised materials, metal-polymers and nanocomposite. Suspension of organic-inorganic nanostructures, containing nanoparticles of noble metals, implemented in the form of poly-complex in two-phase reacting system, consisting of two volume contacting immiscible liquids. Poly-complex includes organic molecules, containing amides in amount 2 or more, and nanoparticles of noble metals. Suspension is received by means of forming of two-phase reacting system, consisting of two contacting volumetric immiscible liquids, addition in it of restorative and synthesis of nanoparticles. Additionally metallised molecules of precursors are dissolved in hydrophobic phase, reducer is added into aqueous phase, and in the capacity of ligands there are used organic molecules, into content of which there are included amides in amount 2 or more. Invention provides receiving of new nano-structured organic-inorganic polymeric complexes on the basis of polyamines, containing nanoparticles of noble metals (Pd, Au) of size up to 10 nm, which allows high specific surface area and are characterised by narrow dispersion of dimensions.
EFFECT: it is provided high density of particles packing in organic-inorganic nano-structures and high performance of transformation of initial material into nanoparticles of noble metals.
23 cl, 12 dwg, 1 ex
SUBSTANCE: invention relates to nanotechnology and can be used for effective change of physicochemical properties of formed on nanoparticles surface inorganic nature of ligand envelope. For receiving of nanoparticles solution with ligand envelope into solution of metal salt in water or organic vehicle is successively introduced stabiliser solution, consisting ligands, and solution of reducer. After it is changed charge sign of ligand envelope by means of one-sided diffusion of substance molecules, changing charge sign of ligand envelope through the semipermeable membrane, into solution of nanoparticles. Additionally it is used membrane, allowing pores size less than size of nanoparticles, but more than size of substance molecules, changing charge sign of ligand envelope. In the capacity of stabiliser it is used substance, molecules' size of which less than size of semipermeable membrane pores.
EFFECT: it is provided receiving of nanoparticles with ligand envelope with specified properties.
2 cl, 2 ex
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.
FIELD: production of new materials.
SUBSTANCE: proposed nanocomposite can be used as component contributing to charges of consumer properties of materials made on its base. Nanocomposite includes fibrils of filler-chitin individualized to nanosizes with distance between fibrils from 709 to 20-22 nm and water-soluble polymeric matrix in interfibril space. Degree of filling of nanocomposite is 0.05-0.25% mass. Fibrils are arranged in parallel and they have cross size of 4 nm. Method of production of nanocomposite comes to the following: free-radical polymerization in water medium of at least one monomer of row of acrylic acid, salt of acrylic acid, acrylamide is carried out in presence of filler. Initiator is chosen from the row of water-soluble peroxides, hydroperoxides or their salts, potassium persulfate. Individualization to nanosizes of fibrils is done simultaneously with process of polymerization and/or with combination of said process with mechanical disintegrating action by disintegrating or pressing, or pressing with abrasion shift. Nanocomposite is obtained in form of film, being pervaporation membrane.
EFFECT: enlarged range of filling, ease of production.
22 cl, 1 tbl, 9 ex, 2 dwg