Method of forming nanosized conducting element

FIELD: physics.

SUBSTANCE: in the method of making a nanosized conducting element, the initial condensation phase is carried out in a medium of inert gases by magnetic sputtering of material from which a nanowire is formed onto a single-crystal chip for a predetermined time interval t, sufficient for detecting separate nucleation centres of the condensed material on steps. A substrate is placed such that the normal to its surface makes an angle with the direction of flow of the condensed atoms, a priori preventing formation of nucleation centres between steps, but sufficient for formation of nucleation centres of the condensed material on the steps. A microphotograph of the surface of the single-crystal chip is then made, from which density of nucleation centres of the condensed material on the steps and distance between the steps are determined, which are used to calculate the time of formation of the nanowire. The final phase of condensation of the material takes place during a time when there is no electrical conductivity between steps.

EFFECT: simple technique of forming solid-state one-dimensional nanostructures from different metals, semiconductors and alloys thereof, having environmental resistance and higher breakdown voltage.

2 cl, 4 dwg

 

The invention relates to the field of microelectronics and nanoelectronics, namely the technology of the formation of ordered nanostructures on a solid surface, and can be used to create a guide, the length of which is several orders of magnitude greater than its diameter (hereafter we will call it the nanowires).

The development of modern nanoelectronics is on track to reduce the size of devices. On the other hand, the classical production methods suited to its natural and technological barrier, when the device size is reduced slightly, but the economic costs increase exponentially. Nanotechnology is the next logical step in the development of high-tech industries. For further progress it is necessary to create materials developed on the basis of nanoparticles with unique characteristics resulting from microscopic sizes of their components.

Nanowires is one of the key objects of nanotechnology. So now is an intensive search for methods for the synthesis of nanowires and structures based on them.

The scope of nanowires is very wide and there are new areas of application of nano-objects. Nanowires can be used for mass production of wires sufficiently large length, which is not bodily to create an electrical nanocable. A promising use of nanowires in conductive tissues and in electronic devices embedded in clothing and also to create transistors [1]. According to [2] the latest application of nanowires are: custom computer memory is 16 kbps, the integral neoplasene electro-optical network, television screens, high-resolution (1011pixels per cm2that much more resolution, currently used), new chemical and biological sensors.

However, technology for the production of nanowires is very difficult and unproductive. Therefore, the creation of new ways of forming discrete nanostructures is crucial for the improvement of microelectronic devices.

Today, there are various methods of creation of ordered nanostructures on the surface of the solid - chemical methods of synthesis, methods of deposition from the vapor or liquid phase growing nanostructures on special substrates. Methods of chemical synthesis can produce different thickness, disordered, confused fiber.

Known for the synthesis of nanowires by vacuum condensation of metals of the 3rd group of the periodic system or of antimony on the crystallographic surface of a silicon (100), which uses a process of self-organization of matter and Samobor is" on the silicon surface [3]. Nanowires formed due to the grouping of dimers adsorbate in long rows. This behavior of the adsorbate due to the large difference of lattice periods of the growing layer and the top layer of the substrate along one of the directions of the crystal.

Similar has several disadvantages: to obtain nanowires as condensed material (condensate) use a limited number of items; a narrow temperature interval create nanowires, because their formation is realized in the temperature range of the substrate 20 to 250°C and, therefore, at low speeds condensation, the formation of nanowires occurs only on a silicon substrate, which is a form of self-organised growth of ordered arrays of nanoclusters with the period of the substrate. The use of other materials as the substrate does not allow the nanowires in this way. This method cannot provide nanowires on the surfaces of the substrate other than the plane of the silicon (100), because other types of planes deposited atoms are placed randomly on the surface, without waiting in lines.

The closest to the technical nature of the claimed is a method of forming a conductive element of nanometer size in a patent [4], adopted for the prototype. In this way defined in the s mode (the rate of condensation, temperature) perform vacuum condensation of metal vapor on the chipped crystals containing stage. In this case, on the substrate are two process that controls the growth kinetics of the embryos (islets) on the steps and active centers: the flow of atoms on a substrate through vacuum condensation and diffusion outflow of adsorbed atoms (adatoms) to the steps and active centers of origin. It uses the mechanism of diffusion of adatoms to the speed of the surface of the substrate or other linear defects. Atoms captured by step, migrate along its edge, pausing for breaks or joining the nuclei. The linear density of nuclei on the steps of the split an order of magnitude greater than the rest of the substrate, which leads to the formation of solid nanowires on the steps earlier than the defect-free substrate comes threshold coalescence (merging).

Prototype method has the following disadvantages:

1. At a relatively low potential difference applied to the substrate, there is an electrical breakdown of the nanowires, i.e. registered electrical conductivity not only along the stages, but also in all other directions. This occurs for the following reason. In islet films nucleation of the crystalline phase under vacuum condensation from the vapor phase occurs on the defects of the substrate [-7]. The crystal surface always contains the active centers of origin. This can be a vacancy in the surface layer when a defective origin, or of the potential well for the adatoms at the defect-free [8]. To the active centers diffuse anatomy, as a result, steps are formed embryos crystals (see figure 1). In island metal films on dielectric, the charge transfer from island to island is by several mechanisms, the most important of which is tunneling. The probability of tunneling increases exponentially with decreasing mastropaolo period, therefore, islet film become conductive before the onset of coalescence. The conductivity island films registered with the characteristic distance between the islets of 10 nm [9]. Voltage applied to the substrate, enables the tunneling process. Through islet film between the steps generate electric currents in unwanted directions, which can lead to failure of the PCB, which uses nanowires.

2. To activate the processes of diffusion method requires heating of the surface. In some cases this is not possible due to thermal instability of the crystal substrate, which is carried out by condensation, and if the nanowires receive the PCB, which already contains thermally unstable elements.

3. To obtain nanowires is necessary to perform a complex calculation of the rate of condensation and the substrate temperature.

4. A large number of marriage that is associated with the fact that real-time condensation in the manufacture of nanowires was found to be greater than the calculated value because of the impossibility of instantaneous termination of the condensation process in the tool for the implementation of vacuum condensation vacuum station).

5. The stoichiometric composition of the nanowires when used as a condensation of material alloys of metals or semiconductors is not permanent, so their use in the prototype is difficult.

The objective of the invention is to increase the reliability of the process of forming a conductive element of nanometer size on the substrate containing the degrees of the chip, reducing the amount of calculations required to select condensation rate of condensation, the temperature of the substrate), the expansion of the range of operating conditions condensation, creating nanowires with a constant stoichiometric composition of the metal alloys and semiconductors, as well as the increase of the voltage level at which the nanowires can function without breakdown.

The technical result of the invention is to provide a simple and effective technologist and the formation of a solid-state one-dimensional nanostructures, resistant to the external environment (temperature, pressure, light, etc. from various metals, semiconductors and their alloys, which allow you to send an electric current larger value without short circuits between adjacent conductive elements at a much higher applied voltage to them than was possible previously.

To achieve a technical result of the claimed method of obtaining a conductive element of nanometer size (nanowires), namely, that:

- get at least one cleaved single crystal containing monohydroxy and/or diatomaceous level;

next inert gas carry out the initial stage of condensation by magnetron sputtering of material from which to form the nanowires (target)on the cleavage of a single crystal within a predetermined period of time t, sufficient for registration of individual embryos condensed material on the steps, the substrate feature so that the normal to its surface made an angle with the direction of flow of the condensed atoms, a priori excludes the formation of embryos between stages, but sufficient for the formation of nuclei of condensation of material on the steps of;

- then produce micrograph of the surface of the cleaved single crystal;

- obtained the micrograph determine the density of nuclei of condensation of material on the steps of the N zstepand the distance between the levels L, which is used for calculating the time of formation of nanowires tf;

next carry out the final stage of magnetron sputtering of material from which to form the nanowire inert gas during the time of condensation of tc=tf-t when there is no electrical conductivity between the steps.

The invention is illustrated by the following drawings:

figure 1 shows the nanowires with increasing 60000 times, formed by the method of the prototype [4];

figure 2 presents nanowires with increasing 60000 times, formed by the present method;

figure 3 shows the device, which can be implemented in the inventive method of obtaining nanowires;

4 shows the block diagram of the algorithm which implements the method according to the present invention.

The inventive method consists in the following.

In any modes (speed condensation temperature by condensation of vapors of any conductive material (metals, semiconductors or their alloys) by magnetron sputtering in an atmosphere of protective gas (e.g. argon) chipped crystals containing steps.

In this case, the substrate is placed at an angle θ between the normal to the surface and the direction of the pot is the AC condensation of atoms, close to 90°. At first glance, condensation on the surface with this arrangement, the substrate is impossible. However, experimental data show that when the magnetron sputtering in condensed stream is a disorientation in the direction of motion of the atoms. This is because the atoms of the condensed material in the form of vapour, experience numerous collisions with atoms of the inert gas and change the direction of its movement. Therefore, the inventive method allows to obtain nanowires by magnetron sputtering and significantly reduce the filling of the substrate between the steps.

The surface of the substrate, obtained by splitting the single crystal has a morphology (relief) in the form of mono - and diatomaceous steps. Unlike the prototype, when such a mutual arrangement of the source of condensed material and the surface, on which is carried out by condensation, anatomy not fall on portions of the substrate that is free of steps and, consequently, to the active centers of origin does not diffuse. Active centers of the surface (vacancies in the surface layer)located between the levels do not affect the process of formation of nanowires.

The main difference of the proposed method from analogs and prototypes is a new principle of the formation of nano awalaki. In the present method of forming nanowires do not use the mechanism of diffusion of adatoms to the steps, because there is no need to control the degree of filling of the substrate between the two stages. For obtaining nanowires in the present method responsible geometrical heterogeneity of the surface of the substrate, which leads to a pronounced selectivity for its completion by condensation.

In the prototype mode condensation suitable for the formation of nanowires is in the range of speeds condensation and temperature of the substrate, in which the steps already formed nanowires, and between the levels experienced a threshold coalescence. Usually, it's a very narrow interval velocities and condensation temperatures of the substrate. The probability of marriage due to a small increase in the duration of condensation and the risk of breakdown between the nanowires through islet film is extremely high.

In the present method increases the time of condensation leads to an increase in diameter of the nanowires, but the breakdown is avoided due to the absence of islets between steps. The advantage of this method include the fact that with its help you can easily change the electrical parameters of the generated one-dimensional nanostructures (different maximum electrical current that they can pass different when the m resistance) due to a change in the thickness of the nanowires. In addition, condensation in the present method can be carried out at arbitrarily low temperatures of the substrate.

Figure 3 presents the algorithm of formation of nanowires, comprising the following steps:

1 - Fabrication of cleaved crystals. Cleaved along the cleavage plane (the most close-Packed plane in the crystal) there are a lot of steps.

2 - the Initial stage of condensation on the cleavage of the crystal. The time of condensation of this stage should be minimal, but sufficient for the formation and registration of individual embryos condensed material in stage (determined resolution means for photographing the surface).

3 - the timing of the initial condensation stage.

4 is a Micrograph of the surface with a means for receiving micrograph of the surface.

5 - Analysis of compliance with location of the substrate relative to the flow of condensed atoms, the condition for the formation of nanowires. This condition is the following: between the steps of filling the substrate condensed material should be equal to zero, i.e. with means for receiving micrograph of the surface does not register the Islands between steps. However, the same tool to obtain micrographs of the surface, which is configured in the same increase should register OST ovci on the steps. If this condition is satisfied, then the angle θ between the direction of the flow of condensed atoms and the normal to the surface of the substrate is chosen correctly, otherwise you must repeat steps 1-5 for the selected system condensate - substrate. The angle θ is different for each system and is close to 90°.

6 - study of the obtained micrograph of the surface, including the determination of the density of embryos in stage and the characteristic distance between the steps.

7 - Calculation of generation time tfnanowires developed by us for the formula:

whereand- constant substrate lattice, m;

Nzstepthe density of embryos in stage, is determined by the micrograph,;

R is the rate of condensation,;

L is the distance between the steps is determined by the micrograph, m

8 - the Final stage of condensation of material on the chipped crystals.

9 is a timing condensation taking into account the initial stage.

10 - Termination of condensation when reaching time values condensation of tf, C.

As a result of performing the above operations, linear defects of the substrate are formed nanowires presented in figure 2.

At a constant rate of condensation, the substrate material and condensation of the mother is La the density of Islands on the speed and the angle θ is there are constant values, so after receiving the micrograph of the chip under specified conditions density data islets used in further production. In this case the condensation is carried out in one stage, and the stages 2-5 are not required.

The inventive method can be implemented using the device presented in figure 4.

Apparatus for producing nanowires contains:

The means 11 for the implementation of condensation (for example, installation of a magnetron sputtering STE MS 46 [10] or its equivalent)that meets the following requirement: the ability of a directional spray of condensate. It includes a means 12 for fixing the substrate on which is formed nanowires.

The means 13 for the manufacture of chipped crystal, placed in a vacuum, similar to the one described in the prototype.

The means 14 for measuring time - for example, time relay series RVV [11], which sends a signal to the end of the work tool for the implementation of condensation.

The means to obtain micrographs of the surface 15, for example, transmission electron microscope, PREM-200 [12].

The inventive method is implemented as follows.

Tool 13 for the manufacture of chipped crystal get the cleavage of the single crystal, which contains steps and/or other linear defects, and also performs the role of the substrate on which I condensed atoms. In the tool 11 to implement the condensation placed the resulting cleavage of the single crystal and condensed material (not shown).

With means for fixing the substrate 12 is fixed to the chip at an angle θ between the normal to its surface and the direction of the flow of condensed atoms. Next, carry out the condensation of material on the fracture of single crystal using the 11 for a small period of time t<tfsufficient for the registration of individual embryos condensed material on the surface of the single crystal. Time measurement is done using the tool 14. After the time t get micrograph of the surface of the chip by using the 15 with the aim of determining the density of nuclei on the steps of the chip and the distance between steps. On the micrograph should not be the germ of a condensate between steps, and the steps you need them. If the condition is not satised, it means that the angle θ is selected incorrectly, and you need to repeat all these steps for using a different value of θ (more if the embryos are between stages, and less if the embryos at the cleavage missing). After receiving the necessary result of the counting time of the formation of nanowires by the formula (1) and continue the condensation in the calculation period (including the time the con is Ansatie at the first stage). At time tfcondensation cease, while on the substrate along the levels of cleaved single crystal nanowires are formed. Their location and their number depends on the method by which the cleavage of the single crystal.

The main advantages of the proposed method in comparison with the prototype are as follows.

1. Nanowires obtained by a specified method, operate at much higher voltage than in the prototype, and, consequently, designed for large values of the electric current that flows through them.

2. The method does not require heating of the surface and, if necessary, can be used at low temperatures. This allows to obtain nanowires on single crystals, not able to withstand high temperatures (for example, crystal CaF2decomposes at high temperatures by the reaction: CaF2→CaF+F [13]).

3. The method does not require complex calculations and theoretical areas of formation of nanowires.

4. The percentage of defects due to incorrectly selected modes of condensation fell.

5. Added the possibility to create nanowires with a constant stoichiometric composition of alloys of metals or semiconductors.

Using the proposed method enables the continuous mass production of nanowires. The substrate may be a DWI is usausa belt conveyor, on one part which will be condensation, and on the other side ready to play nanowires.

Thus, when using the invention can be made of solid nanowires of desired length, which depending on the material can be conductive, electric current or a semiconductor. Due to the possibility to choose the chemical composition of the nanostructures in a wide range, they have the strength and resistance to the external environment (temperature, pressure, light, chemical resistance and so on), as well as other desirable properties inherent in the substance of which they are formed. In addition, they are able to conduct an electric current at high potential difference and the absence of a short circuit, i.e. have a higher breakdown voltage.

It is also important that they can form a well-organized arrays of conductive elements of the desired configuration and of great length, with each element of the array is electrically isolated from the neighbors.

Sources of information

1. A.N. Aleshin. Quasi-one-dimensional transport in conducting polymer nanowires /Anglesin // FTT. - 2007. - V.49. No. 11. - S-1940.

2. The world of materials and technologies. Nanostructured materials, Ed. Nieborow. - M.: The Technosphere. - 2009. - 487 S.

3. V.G. Kotlyar low-Dimensional structure of the metal is s on the surface of the silicon / Ughts, Say, Aveston etc. // Vestnik DVO ran. - 2005. No. 1. - S-115.

4. Method of forming a conductive element nanometer size / Dubovskov, Nieslen, Ewido // Patent RF №2401246, 2010.

5. Kosevich V.M. Centers of nucleation of condensed phases in ionic crystals / Vmmouse, Lseparate, AAA and other Reports of Acad. Of Sciences of the USSR. 1968. - T. No. 3. - P.586-588.

6. The V.M. Ievlev Oriented crystallization of films: textbook. manual / Wmiii, Avibugeo. - Voronezh: VSTU, 1998. - 216 C.

7. Kukushkin S.A. the Processes of condensation of thin films / Sagalowsky, Avision // Phys. - 1998. - T. No. 10. - S-1116.

8. Cowards LI Islet metal film / Ligtroom, Vahamaki. - M.: metallurgy, 1973. - 321 S.

9. Borzak p. g Electronic processes in islet metallic films / Pegbars, Wailupe. - Kiev: Naukova Dumka, 1980. - 239 S.

10. Installation magnetron sputtering STE MS 46 / - Electron. Dan. - Mode of access: http://www.rusnanonet.ru/equipment/ste ms46/ (25.09.2011).

11. JSC "TAU - time relay series "RVV". An electron. Dan. - Mode of access: http://www.tau-spb.ru. (25.06.2011).

12. Voronezh state technical University. - Electron, Dan. - Mode of access: http://www.vorstu.ru/region/2065/. (25.06.2011).

13. Storm = Fundamentals of metallurgical processes during welding. - Electron, Dan. - Mode of access: http://www.shtorm-its.ru (17.02.11).

1. A method of obtaining a conductive element of the home is the world size (nanowires), namely, that:
receive at least one cleaved single crystal containing monohydroxy and/or diatomaceous speed;
next, inert gas carry out the initial stage of condensation by magnetron sputtering of material from which to form the nanowire on the cleavage of a single crystal within a predetermined period of time t, sufficient for registration of individual embryos condensed material on the steps, the substrate feature so that the normal to its surface made an angle with the direction of flow of the condensed atoms, a priori excludes the formation of embryos between stages, but sufficient for the formation of nuclei of condensation of material on the steps of;
then produce micrograph of the surface of the cleaved single crystal;
on the obtained micrograph determine the density of nuclei of condensation of material on the steps of the Nzstepand the distance between the levels L, which is used for calculating the time of formation of nanowires tf;
then carry out the final stage of the condensation of the material during the time of condensation of tc=tf-t when there is no electrical conductivity between the steps.

2. The method according to claim 1, in which the timing of the formation of nanowires tfcarried out according to the formula:
img src="http://img.russianpatents.com/1133/11335133-s.jpg" height="14" width="34" />
where a is a constant of the crystal lattice of the substrate, m;
R - condensation rate, 1/m2·c.



 

Same patents:

FIELD: physics.

SUBSTANCE: method of forming contact drawing from nickel on silicon wafers involves formation of a dielectric film with windows, chemical deposition of nickel in said windows and formation of a nickel silicide interlayer from the gas phase during thermal decomposition of nickel tetracarbonyl vapour at temperature 200-300°C, pressure in the system of (1-10)-10-1 mm Hg and rate of supplying nickel tetracarbonyl vapour equal to 0.5-2 ml/min per dm2 of the covering surface. The nickel layer is then removed up to the nickel silicide layer through chemical etching and nickel is deposited via chemical deposition onto the nickel silicide interlayer in the window of the dielectric film.

EFFECT: invention enables formation of a transparent contact for an electroconductive layer based on nickel with low ohmic resistance, independent of the type of conductivity and degree of doping of the silicon surface.

1 ex, 1 tbl

FIELD: physics; conductors.

SUBSTANCE: invention relates to semiconductor micro- and nanoelectronics and can be used in making integrated circuits, in making electrodes in transistors and capacitor plates, in making contacts and conduction regions on a silicon surface, as conducting, thermostable and barrier layers in metallisation systems. The method of making a thin-film metal structure of tungsten on silicon involves making a nanometer sublayer of an adhesion promoter on a silicon substrate and subsequent deposition of a thin film of tungsten through gas-phase chemical deposition through reduction of tungsten hexafluoride with hydrogen at low pressure. The adhesion promoter used is tungsten silicide W5Si3.

EFFECT: invention improves quality of the obtained metal structure of tungsten on silicon with simplification of the process at the same time.

3 cl, 1 dwg, 3 ex

FIELD: light devices production.

SUBSTANCE: method of quantum wells mixing within semiconductor device implies: a) formation of layer structure with quantum wells including doped upper layer; b) formation of etch preventing layer over mentioned upper layer; c) formation of temporary layer over mentioned etch preventing layer, and mentioned etch preventing layer has significantly lower etch rate than mentioned temporary layer on condition that etching requirements are preliminary specified; d) process of quantum wells mixing upon device structure making significant violation of at least a part of consumed layer; e) removal of temporary layer from at least device contact area by etching selective relative to etch preventing layer to uncover mentioned etch preventing layer within contact area; and f) formation of contact over layer structure with quantum wells directly on the surfaced uncovered after execution of stage e) at least within mentioned contact area.

EFFECT: improvement of device contact resistance.

15 cl, 10 dwg

The invention relates to a process of coating with plasma polymer coatings (thin films) on the surface of the objects for various purposes, made of various materials, and can be used in microelectronics for applying resistin, and passivating dielectric layers, in the medical industry for the application of corrosion protective coatings on surgical instruments and medical equipment, with the same purpose in the production of chemical ware, in the textile industry to impart to the fibers or tissues ready hydrophobic properties by coating on the surface of a thin layer of polymer, and in other areas

FIELD: metallurgy.

SUBSTANCE: invention relates to casting critical parts to be operated at high loads at 300-350°C, e.g. ICE components, valves and accessories of hydraulic works, stages of borehole pumps, heating radiator parts, etc. Proposed composition contains the following substances, in wt %: 1.5-2.5 Ni; 1-2 Mn; 0.3-0.7 Fe, 0.2-0.6 Zr, 0.02-0.12 Sc, 0.002-0,1 Ce, at content of zirconium and scandium satisfying the condition 0.44<2·CZr+CSc<0.64. Note here that said zirconium and scandium exist in alloy structure as Al(Zr,Sc) phase with Ll2 crystal lattice and mean size of nanoparticles not exceeding 20 nm.

EFFECT: new sparingly alloyed refractory alloy.

1 tbl, 4 ex, 3 dwg

FIELD: metallurgy.

SUBSTANCE: beta-titanium alloy with ultrafine-grained structure consists of beta-phase gains with mean size not exceeding 0.5 mcm, precipitations of secondary alpha-phase particles of spherical shape and mean size not exceeding 0.5 mcm and volume fraction in the structure making at least 40%. Proposed method comprises intensive plastic deformation and thermal treatment. Thermal treatment is carried out before deformation by heating to temperature exceeding that of polymorphic conversion by 5-15°C for, at least, one minute for 1 mm of diameter cross-section and quenching in water. Intensive plastic deformation is performed by equal-channel angular pressing with changing deformation direction through 90 degrees after every deformation cycle at (T"пп"-200…T"пп"-150)°C with total accumulated deformation e≥3.5 and subsequent quenching in water.

EFFECT: higher strength and fatigue characteristics of alloys.

2 cl, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: thermoplastic foam material consists of expandable thermoplastic particles containing a polymer matrix which consists of a styrene polymer, polyolefin and a hydrogenated or non-hydrogenated styrene-butadiene block copolymer, which form a continuous phase rich in the styrene polymer and a dispersed phase rich in polyolefin. The foam material has cells with average size ranging from 50 mcm to 250 mcm. The cladding of the cells has a nano-cellular structure with pore diameter of 100-500 nm. The method of producing thermoplastic foam materials from said particles consists of the following steps: a) obtaining a polymer matrix by mixing said thermoplastic polymers, b) the obtained polymer matrix is saturated with a foaming agent and granulated to obtain expandable thermoplastic polymer particles, c) the expandable thermoplastic polymer particles are pre-foamed to obtain particles of foam material, and d) the pre-foamed particles of foam material are welded in a mould under the action of hot air or steam to obtain moulded articles from foam material consisting of particles at operating pressure which is set sufficiently low in order to preserve the nano-cellular structure in the cladding of the cells.

EFFECT: design of a method and obtaining expandable thermoplastic polymer particles with low loss of the foaming agent and high expandability, which can be processed to obtain foam materials made of particles with high flexural rigidity and good elasticity at the same time.

5 cl, 4 tbl, 2 dwg, 13 ex

FIELD: radio engineering, communication.

SUBSTANCE: disclosed is a polymer which is obtained from a polyamine acid or a polyimide, which contains picopores, the polyamine acid and polyimide having a structural repeating unit obtained from an aromatic diamne, which contains at least one functional group which is located in an ortho-position to the amino group, and a dianhydride. Methods of obtaining said polymer from a polyamine acid and a polyimide, as well as an article made from said polymer are also disclosed.

EFFECT: disclosed polymer has high permeability and selectivity for small molecules, high thermal stability, chemical resistance and good solubility.

42 cl, 6 tbl, 55 ex, 12 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to colloidal solutions of different nano-forms of hexagonal boron nitride (h-BN) in liquid media, and specifically to obtaining hexagonal boron nitride (h-BN) which is soluble in water and polar solvents. The method of obtaining soluble hexagonal boron nitride involves mixing hexagonal boron nitride with a functionalising agent. The reaction mixture is then heated and the obtained product is dissolved in a solvent with ultrasonic action and the solution of the end product is separated. The functionalising agent used is hydrazine or a mixture of nitric acid and sulphuric acid or oleum. The reaction mixture is dispersed by ultrasound with subsequent heating and periodic ultrasonic dispersion during heating. The process is carried out in a closed volume. The obtained product is dispersed by ultrasound in water or a polar organic solvent.

EFFECT: method enables to simplify and increase efficiency of producing soluble functionalised h-BN by increasing output of soluble h-BN and using cheaper technologically acceptable functionalising agents.

4 cl, 1 dwg, 3 ex

FIELD: electrical engineering.

SUBSTANCE: method for formation of conductors in nanostructures involves application onto the substrate of the initial dielectric substance into the molecules whereof metal atoms are included, complete removal non-metal atoms from the substance in the chosen sections by way of the dielectric substance radiation, through a mask, with a beam of accelerated particles and repeated radiation of the said sections with beams of accelerated ions or non-metal atoms included into the composition of the initial dielectric substance with the dose ensuring reduction of volume of the metal conductors formed in the process of primary radiation.

EFFECT: reduction of sizes of conductors formed, expansion of the range of materials used, simplification of requirements to sizes ratio in the mask.

1 dwg

FIELD: metallurgy.

SUBSTANCE: invention refers to plasma technology, and namely to plasma treatment method of disperse material. It can be used for obtaining coated polymer powder nanocomposite materials. Polymer powder is placed in a discharge chamber with an electrode system, which is then vacuumised. Then, helium mixed with reactant gas is supplied at pressure of 100÷140 Pa to the discharge chamber operating under low vacuum conditions. Pulse arc discharge with discharge current force I equal to 2÷3 kA is created. Pulse duration τ is set in the range of 20÷300 mcs and pulse repetition frequency f is set to 0.5÷1 kHz. At the same time, gas mixture supplied at pressure of 100÷140 Pa is ionised by means of pulse arc discharge, and nanoparticles of oxides, nitrides or carbides of metals are obtained by sputtering the consumed solid electrode. Obtained flow of nanoparticles is deposited to the surface of polymer particles of the powder uniformly mixed in vertical plane so that powder is obtained from polymer particles with the coating representing agglomerated nanoparticles of oxides, nitrides or carbides of metals.

EFFECT: obtained material has high mechanical strength and high elasticity modulus at maintaining high deformability.

1 cl, 1 dwg, 4 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic materials science and methods of producing beta-ray emitting materials based on oriented pyrolytic graphite. The process of intercalating a tritium additive into oriented graphite with thermal-neutron capture cross-section of about (4.5-6.0)10-3 barn is carried out in two consecutive steps. At the first step, graphite and a natural mixture of lithium isotopes are placed in a vacuum chamber, the graphite itself being placed between two electrically insulated plates whose C axis lies perpendicular to the surface of the plates. In the vacuum conditions, the graphite and the natural mixture of lithium isotopes are simultaneously heated to obtain intercalated compounds with a graphite composition of LiC6 or LiC12, which are placed in the reactor core and at room temperature are irradiated with a neutron flux of about 1014 cm-2 s-1 until full tritium isotope uptake as a result of a nuclear reaction.

EFFECT: invention enables to obtain graphene cells oriented in pyrolytic graphite with tritium additives in pure form or in form of lithium and tritium compounds.

7 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in motorcar, chemical, electronic and electrochemical industry, as well as hydrogen power engineering. First, nanoparticles of a metal catalyst - Pd, Pt, Ni, Ti, Fe, Co, Nb, Mo, Ta, W, Rh, Ru, Os, Ir, La, Mg and/or alloys thereof are placed in inter-fragment regions of carbon nanomaterial - graphite nanofibres or carbon nanotubes. The carbon nanomaterial is then cleaned from attached oxide-type functional groups by burning in an inert gas at 773 K. A layer of chemisorbed hydrogen with thermal desorption activation energy of about 1.2 eV is then formed on the inter-fragment surfaces and a layer of chemisorbed hydrogen with thermal desorption activation energy of about 2.5 eV is formed on graphene inner surfaces by holding the carbon nanomaterial in a current of gaseous molecular hydrogen at temperature of 773 K. Final hydrogenation of the carbon nanomaterial is carried out in a container at pressure, temperature and time of not more than 300 bar, 1000 K and 300 h, respectively, until obtaining 10 wt % or more of highly compact hydrogen with density in the order of 1 g/cm3 which is intercalated in the carbon nanomaterial.

EFFECT: invention reduces the pressure and temperature when producing highly compact hydrogen, enables to use simple, available and low power consumption equipment, and provides prolonged storage of hydrogen at room temperature.

2 cl, 3 dwg, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of fibrous filtration materials, particularly, those of polyamide nanofibres. Nanofibres are made by electrostatic forming and feature diameter of 70 nm to 300 nm at standard deviation of fibre mean diameter not exceeding 30% and unit area weight of 0.02 g/m2 to 1.2 g/m2. Material is arranged on nonwoven substrate from polymer microfibres. Nanofibre is produced in compliance with Nanospider technology by electrostatic forming in high-voltage field generated between charged forming electrode and precipitation electrode. Fibres are formed from polyamide solution with polyamide concentration of 6 wt % to 12 wt % in the mix of formic and acetic acids taken at the ratio of 1:2, respectively. Produced material is used as working layer of individual respirators.

EFFECT: efficient retention of aerosol particles.

5 cl, 2 dwg, 1 tbl, 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.

2 cl

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

FIELD: carbon materials.

SUBSTANCE: powderlike catalyst is continuously fed into tubular reactor and displaced along reactor axis. Following composition of catalyst can be used: 70-90% Ni and 10-30% MgO or 40-60% Co and 40-60% Al2O3, or Mo, Co, and Mg at molar ratio 1:5:94, respectively. Process is carried out continuously at countercurrent catalyst-hydrocarbon contact. In the first zone(s) catalyst is activated by gases leaving hydrocarbon pyrolysis at 450-600°C. Residence time of catalyst ranges from 5 to 180 min. Activated catalyst is passed into pyrolysis zone(s) at 550-1000°C. Into the same zone(s), hydrocarbons, e.g. methane, are countercurrently passed. Residence time of catalyst in pyrolysis zone(s) ranges from 0.5 to 180 min. Invention can be used in sorbent, catalyst, and composite manufacturing processes.

EFFECT: enabled continuous manufacture of layered nanotubes or bent hollows fibers, reduced number of stages and consumption of reagents.

4 cl, 2 dwg, 7 ex

FIELD: production of anti-bacterial and sterilizing substances, conducting adhesives and inks and protective screens of graphical displays.

SUBSTANCE: proposed colloidal solution is prepared through dissolving the metal salt and water-soluble polymer in water and/or nonaqueous solvent. Then, reaction reservoir with solution thus obtained is blown with gaseous nitrogen or argon and is subjected to radioactive radiation, after which solution is additionally diluted and treated with ultrasound. Used as metal salt is silver salt, for example nitrate, perchlorate, sulfate or acetate. Use may be also made of nickel, copper, palladium or platinum salt. Used as polymer is poly vinyl pyrrolidone, copolymer of 1-vinyl pyrrolidone with acryl or vinyl acetic acid, with styrene or vinyl alcohol. Used as nonaqueous solvent is methanol, ethanol, isopropyl alcohol or ethylene glycol. In production of metal-polymer nano-composites, use may be made of polymer stabilizer, for example, polyethylene, polyacrylonitrile, polymethyl methocrylate, polyurethane, polyacrylamide or polyethylene glycol instead of water-soluble polymer. In this case, surfactant may be additionally introduced into reaction reservoir for obtaining the emulsion. Solution remains stable for 10 months at retained shape of particles and minor increase of their size. Freshly prepared colloidal solution contains nano-particles having size not exceeding 8 nm.

EFFECT: smooth distribution of nano-particles of metal in polymer.

24 cl, 13 dwg, 1 tbl, 7 ex

FIELD: nanoelectronics, microelectronics; microelectronic and microelectromechanical systems; manufacture of micro- and nanoprocessors and nanocomputers.

SUBSTANCE: proposed method consists in bringing the electrode to substrate surface, after which electrostatic potential which is negative relative to substrate surface point is fed to electrode; substrate is preliminarily placed in damp atmosphere and water adsorption film is formed on its surface, after which electrode is brought to substrate surface in such way that water adsorption film wets electrode; electrode is brought in contact with substrate surface; simultaneously with feed of electrostatic potential to electrode and electrode is subjected to pressure relative to substrate surface.

EFFECT: increased penetration into substrate volume (from 10 nm to 50 nm) of dielectric sections of oxide films.

17 cl, 3 dwg, 5 ex

FIELD: nano-engineering; manufacture of nano-structures; methods of production of nano-fibers.

SUBSTANCE: proposed method consists in forming multi-layer structure on substrate; multi-layer structure includes at least one sacrificial layer and film structure from agent used for forming the fibers and divided into narrow strips; sacrificial layer is selectively removed and narrow strips are released from substrate, thus forming fibers. Multi-layer structure may include several sacrificial layers and several layers from which fibers will be formed. Film structure is divided into strips after growing or it is initially divided into narrow strips by forming it on special-pattern substrate. Proposed method makes it possible to obtain nano-fibers possessing high strength and resistance to surrounding medium. Process is compatible with standard technologies of manufacture of integrated circuits.

EFFECT: enhanced efficiency.

10 cl, 4 dwg

FIELD: microelectronics, nanoelectronics, and semiconductor engineering; producing quantum device components and quantum-effect structures.

SUBSTANCE: proposed method for producing quantum dots, wires, and components of quantum devices includes growing of stressed film from material whose crystalline lattice constant is higher than that of substrate material. Thickness of stressed film being grown is smaller than critical value and film is growing as pseudomorphous one. Sacrificial layer is grown between stressed film and substrate which is then selectively removed under predetermined region of film thereby uncoupling part of the latter from substrate; this part is bulged or corrugated with the result that film stress varies causing shear of conduction region bottom (top of valence region) and formation of local potential well for carriers. In addition, stressed film may be composed of several layers of different materials; it may also have layer mainly holding charge carriers and layer practically free from charge carriers.

EFFECT: facilitated manufacture of quantum structures, enlarged range of materials used, and improved characteristics of components produced.

4 cl, 7 dwg

Up!