Laser fluoride nanoceramic and method for production thereof |
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IPC classes for russian patent Laser fluoride nanoceramic and method for production thereof (RU 2484187):
 Polymer nanoparticles containing medium for photon up-conversion / 2479616
Polymer nanoparticles contain a medium for photon up-conversion and a stabilising agent. Said medium contains a polymer matrix having two organic components distributed therein. The first component is capable of absorbing light at a first wavelength in the range w≤λ1≤x and acts as a sensitiser in said medium. The second component is capable of emitting light at a second wavelength in the range y≤λ2≤z, where λ2≤λ1, and acts as an emitting component in said medium. The stabilising agent is selected from hydrophilic or amphiphilic polymers.
Method of changing normal refraction index of nonlinear gase crystal / 2472876
Invention can be used when making parametric frequency converters of laser radiation in the middle infrared and terhertz spectral range. The normal refraction index of a nonlinear GaSe crystal is changed by doping with chemical element Al with a small size compared to the chemical element Ga in concentration of 0.005-0.05 wt %.
 Solid-state electromagnetic radiation source / 2464683
Solid-state electromagnetic radiation source has a working layer in form of a film of conducting ferromagnetic material, a first electrode made from conducting ferromagnetic material which is in contact with the working layer, and a second electrode made from conducting material which is in contact with the working layer. The working layer of the solid-state source lies on a substrate made from a dielectric or a semiconductor which is transparent for radiation in the operating wavelength range. The second electrode is in form of a solid plate with a through-hole lying on the surface of the working layer. The first electrode is in form of a rod with a pointed end, which is inserted into the hole of said plate such that the face of its pointed end is in contact with the working layer.
 Optical quantum generator of two-micron wavelength range / 2459328
Optical quantum generator has a resonator comprising at least two mirrors, in which there is an active medium made from lutetium oxide ceramic Lu2O3 doped with thulium ions Tm3+, and the optical pumping source used is at least one laser diode with emission on a wavelength selected in the 774-812 nm range.
Method of producing fluoride nanoceramic / 2436877
Method involves thermomechanical processing of initial crystalline material made from metal halides at plastic deformation temperature, obtaining a polycrystalline microstructured substance characterised by crystal grain size of 3-100 mcm and intra-grain nanostructure, where thermomechanical processing of the initial crystalline material is carried out in vacuum of 10-4 mm Hg, thus achieving degree of deformation of the initial crystalline material by a value ranging from 150 to 1000%, which results in obtaining polycrystalline nanostructured material which is packed at pressure 1-3 tf/cm2 until achieving theoretical density, followed by annealing in an active medium of a fluorinating gas. The problem of obtaining material of high optical quality for a wide range of compounds: fluoride ceramic based on fluorides of alkali, alkali-earth and rare-earth elements, characterised by a nanostructure, is solved owing to optimum selection of process parameters for producing a nanoceramic, which involves thermal treatment of the product under conditions which enable to increase purity of the medium and, as a result, achieve high optical parameters for laser material.
 Polycrystalline laser material / 2431910
Polycrystalline laser material is a microstructured substance with grain size from 3 mcm and consists of calcium and ytterbium fluorides. The material is a solid solution of calcium fluoride and ytterbium fluoride. Content of ytterbium fluoride is less than 5 mol %. The base of the structure of the material is composed of layered grains in which layer thickness ranges from 30 to 100 nm, and the size of separate grains ranges from 30 to 150 mcm.
 Laser gain medium and laser generator (versions) using said medium / 2427061
Laser medium includes an optical medium which can transmit a laser beam and having an input surface, a first surface and a second surface opposite the first surface. At least one of the gain media is connected to the first surface of the optical medium and at least one of the gain media is connected to the second surface. The gain media are pumped by an optical pumping beam and amplify the laser beam during its successive reflection. The gain media are made from the same optical material and are doped with at least one active element. The amount of the doping active element in the gain media and/or thickness of the gain media in the direction perpendicular to the first or second surfaces is chosen such that the amount of heat released during absorption of the optical pumping beam is the same for the said gain media.
 Laser material / 2395883
Proposed laser material features garnet structure R3T5O12, where R is ions selected from the group Y, La, Ce, Gd, Sc, Lu; T is ions selected from the group Al, Ga, Sc, Lu. Laser material comprises ion of trivalent hafnium as activator. Activator concentration varies from 0.05 to 5 % by weight in terms of hafnium dioxide in excess of garnet stoichiometric formula. Said laser material can represent an optical ceramic, monocrystal or monocrystalline film.
 Laser material / 2391754
Laser material has a garnet structure R3T5O12. R denotes ions selected from Y, La, Ce, Gd, Sc, Lu. T denotes ions selected from Al, Ga, Sc, Lu. The laser material contains active ions of trivalent neodymium and a sensitising agent. The sensitising agent used is at least one ion selected from a group of trivalent ions of titanium, zirconium and hafnium.
 Laser material / 2369670
Invention relates to electronic engineering material and can be used in making new devices in photonics, quantum electronics and ultraviolet optics. The laser material, based on barium and yttrium fluoride crystal, activated by trivalent ions of cerium BaY2F8:Ce3+, additionally contains ytterbium and lutetium ions in concentration of 0.5-5.0 at % and 1-5 at %, respectively.
 Method of diamond heat treatment / 2471542
Invention relates to processes used in operation at high pressure and modifying substances physically. Proposed method comprises placing diamond in reaction cell in pressure transmitting medium, increasing pressure in reaction chamber and it cooling. Note here that thermal treatment is carried out at temperature increase rate of 10-50°C/s and at 2000-2350°C by passing electric current via heater in cell from programmed power supply source with due allowance for temperature relaxation in said cell in heating. For this, note also that temperature relaxation constant is defined. Said cell is cooled after heating by switching off power supply in forming short diamond heating pulse in temperature range of over 2000°C with diamond total stay time smaller than 30 seconds. Allowance for temperature relaxation in said cell in heating for heating rate Vt and pre-definition of cell temperature relaxation constant τ is made by setting in said programmable power source the maximum temperature of heating to τVT above maximum treatment temperature of 2000-2350°C.
Method of thermal treatment of abrasive tool (at) / 2467100
Invention relates to production of abrasive tools intended for machining metals and alloys. Proposed cycle of processing AT at TTB comprises heating AT at 2450 Hz in microwave chamber for near-100 mm-thick AT and at 890-915 Hz for over-100 mm-thick AT to complete polymerisation (hardening) and curing semis at said temperature with uniform forced removal of volatile matters released therefrom (hot vapor-gas mix) from thermostat free volume by airflow created by exhaust vent system of microwave chamber via slots made in thermostat front and rear walls to rule out saturation of said volatile matters. Temperature of processed semis is controlled by device incorporated with thermostat and airflow forced in thermostat is heated to temperature of semis.
 Method of diamond processing / 2451774
Invention relates to diamond processing, in particular, by thermochemical process. Proposed method comprises applying layer of spirit glue composition onto diamond surface, said composition containing transition metal, for example, Fe, Ni or Co, and processing diamond thermally at temperature not exceeding 1000°C. To prepare spirit glue composition, powder of water-soluble salt of transition metal is used. Said powder in amount of 1-10 wt % of water solution is mixed with spirit solution of glue at salt water solution-to-glue spirit solution ratio of 1:1. Prepared mix is applied on diamond surface in 10-20 mcm-thick layer to be dried. Thermal processing of diamond is performed in two steps. Note here that, at first step, diamond is processed at 600-700°C for 1-2 min, while, at second step, it is processed at 800-1000°C for 15-30 min.
Method of producing fluoride nanoceramic / 2436877
Method involves thermomechanical processing of initial crystalline material made from metal halides at plastic deformation temperature, obtaining a polycrystalline microstructured substance characterised by crystal grain size of 3-100 mcm and intra-grain nanostructure, where thermomechanical processing of the initial crystalline material is carried out in vacuum of 10-4 mm Hg, thus achieving degree of deformation of the initial crystalline material by a value ranging from 150 to 1000%, which results in obtaining polycrystalline nanostructured material which is packed at pressure 1-3 tf/cm2 until achieving theoretical density, followed by annealing in an active medium of a fluorinating gas. The problem of obtaining material of high optical quality for a wide range of compounds: fluoride ceramic based on fluorides of alkali, alkali-earth and rare-earth elements, characterised by a nanostructure, is solved owing to optimum selection of process parameters for producing a nanoceramic, which involves thermal treatment of the product under conditions which enable to increase purity of the medium and, as a result, achieve high optical parameters for laser material.
 Procedure for surface of diamond grains roughing / 2429195
Procedure for surface of diamond grains roughing consists in mixing diamond grains with metal powder and in heating obtained mixture to temperature of 800-1100°C in vacuum as high, as 10-2-10-4 mm. As metal powders there are taken powders of iron, nickel, cobalt, manganese, chromium, their alloys or mixtures. Powders not inter-reacting with diamond grains at heating can be added to the mixture.
Method of annealing crystals of group iia metal fluorides / 2421552
Method involves subjecting a grown and hardened, i.e. correctly annealed crystal, to secondary annealing which is performed by putting the crystal into a graphite mould, the inner volume of which is larger than the crystal on diameter and height, and the space formed between the inner surface of the graphite mould and the surface of the crystal is filled with prepared crumbs of the same material as the crystal. The graphite mould is put into an annealing apparatus which is evacuated to pressure not higher than 5·10-6 mm Hg and CF4 gas is then fed into its working space until achieving pressure of 600-780 mm Hg. The annealing apparatus is then heated in phases while regulating temperature rise in the range from room temperature to 600°C, preferably at a rate of 10-20°C/h, from 600 to 900°C preferably at a rate of 5-15°C/h, in the range from 900 to 1200°C preferably at a rate of 15-30°C/h, and then raised at a rate of 30-40°C/h to maximum annealing temperature depending on the specific type of the metal fluoride crystal which is kept 50-300°C lower than the melting point of the material when growing a specific crystal, after which the crystal is kept for 15-30 hours while slowly cooling to 100°C via step-by-step regulation of temperature decrease, followed by inertial cooling to room temperature.
 Method of thermal treatment of single-crystal substrate znte and single-crystal substrate znte / 2411311
Method includes the first stage of increasing temperature of single-crystal substrate ZnTe up to the first temperature of thermal treatment T1 and maintenance of substrate temperature within specified time; and the second stage of gradual reduction of substrate temperature from the first temperature of thermal treatment T1 down to the second temperature of thermal treatment T2, lower than T1 with specified speed, in which T1 is established in the range of 700°C≤T1≤1250°C, T2 - in the range of T2≤T1-50, and the first and second stages are carried out in atmosphere of Zn, at the pressure of at least 1 kPa or more, at least 20 cycles or at least 108 hours.
 Method of growing heat resistant monocrystals / 2404298
Crystals are grown using the Kyropoulos method with an optimum annealing mode, carried out while lowering temperature of the grown monocrystal to 1200°C at a rate of 10-15°C/hour and then cooling to room temperature at a rate of 60°C/hour.
Method of producing monocrystals of calcium and barium flourides / 2400573
Method involves crystallisation from molten mass through Stockbarger method and subsequently annealing the crystals through continuous movement of the crucible with molten mass from the upper crystallisation zone to the lower annealing zone while independently controlling temperature of both zones which are separated by a diaphragm. The crucible containing molten mass moves from the crystallisation zone to the annealing zone at 0.5-5 mm/h. Temperature difference between the zones is increased by changing temperature in the annealing zone proportional to the time in which the crucible moves from the beginning of crystallisation to its end, for which, while maintaining temperature in the upper crystallisation zone preferably at 1450-1550°C, in the lower annealing zone at the beginning of the crystallisation process temperature is kept at 1100-1300°C for 30-70 hours, thereby ensuring temperature difference of 450°C between the zones at the beginning. Temperature of the annealing zone is then lowered to 500-600°C in proportion to the speed of the crucible with the growing crystal. Temperature of the annealing zone is then raised again to 1100-1300°C at a rate of 20-50°C/h, kept for 18-30 hours after which the zone is cooled to 950-900°C at a rate of 2-4°C/h, and then at a rate of 5-8°C/h to 300°C. Cooling to room temperature is done inertially. Output of suitable monocrystals of calcium and barium fluorides with orientation on axes <111> and <001>, having high quality of transparency, uniformity, refraction index and double refraction is not less than 50%.
 Superstrong single crystals of cvd-diamond and their three-dimensional growth / 2389833
Method includes placement of crystalline diamond nucleus in heat-absorbing holder made of substance having high melt temperature and high heat conductivity, in order to minimise temperature gradients in direction from edge to edge of diamond growth surface, control of diamond growth surface temperature so that temperature of growing diamond crystals is in the range of approximately 1050-1200°C, growing of diamond single crystal with the help of chemical deposition induced by microwave plasma from gas phase onto surface of diamond growth in deposition chamber, in which atmosphere is characterised by ratio of nitrogen to methane of approximately 4% N2/CH4 and annealing of diamond single crystal so that annealed single crystal of diamond has strength of at least 30 MPa m1/2.
Method of producing fluoride nanoceramic / 2436877
Method involves thermomechanical processing of initial crystalline material made from metal halides at plastic deformation temperature, obtaining a polycrystalline microstructured substance characterised by crystal grain size of 3-100 mcm and intra-grain nanostructure, where thermomechanical processing of the initial crystalline material is carried out in vacuum of 10-4 mm Hg, thus achieving degree of deformation of the initial crystalline material by a value ranging from 150 to 1000%, which results in obtaining polycrystalline nanostructured material which is packed at pressure 1-3 tf/cm2 until achieving theoretical density, followed by annealing in an active medium of a fluorinating gas. The problem of obtaining material of high optical quality for a wide range of compounds: fluoride ceramic based on fluorides of alkali, alkali-earth and rare-earth elements, characterised by a nanostructure, is solved owing to optimum selection of process parameters for producing a nanoceramic, which involves thermal treatment of the product under conditions which enable to increase purity of the medium and, as a result, achieve high optical parameters for laser material.
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FIELD: chemistry. SUBSTANCE: fluoride nanoceramic is obtained by thermomechanical treatment of the starting crystalline material made from CaF2-YbF3, at plastic deformation temperature to obtain a workpiece in form of a polycrystalline microstructured substance, which is characterised by crystal grain size of 3-100 mcm and a nanostructure inside the grains, by annealing on air at temperature of not less than 0.5 of the melting point with compaction of the obtained workpiece in a vacuum at pressure of 1-3 tf/cm2 until the end of the deformation process, followed by annealing in an active medium of carbon tetrafluoride at pressure of 800-1200 mmHg. The starting crystalline material used can be a fine powder which has been subjected to heat treatment in carbon tetrafluoride, or a moulded workpiece of crystalline material made from the powder and heat treated in carbon tetrafluoride. EFFECT: invention enables to obtain a fluoride nanoceramic with high degree of purity and high uniformity of the structure of said optical material. 4 cl, 3 ex
The invention relates to a technology for optical polycrystalline materials, namely fluoride ceramics with nano-sized structure and improved optical, laser and laser characteristics. Optical ceramics, thanks to the improved, in comparison with single crystals and glasses, mechanical and thermomechanical properties, has found its application as structural elements of optics, which during operation are subjected to mechanical loads, temperature changes and contact with atmospheric moisture. Uniform distribution of the various components in the composition of the ceramic gives you the ability to synthesize a variety of compounds, including a high content of laser ion that is unattainable for crystals. The most widely fluoride ceramics on the basis of fluorides of alkali, alkaline earth and rare earth metals. Obtaining ceramics by hot recrystallization pressing powders of fluoride is not possible to synthesize a material with high transparency and optical homogeneity, and in the case of ceramics, assisted laser ions cannot reach the low threshold and high efficiency generation of laser radiation. Poor transparency and optical homogeneity ceramics are the result of prisutstvie is it microscopic pores and voids, educated at the grain boundaries of the crystallites on the surface of which is localized various impurities (CO2, HE, H2O) and the concentration of the defects caused by inhomogeneous distribution of alloying due to its interaction with impurities. To improve the optical characteristics of fluoride ceramics using such techniques as the heat treatment of the raw powder by gas-reducing agent or gas-fluorinating agent, using as raw material powders gidrohloridu alkali and alkaline earth metals, conducting secondary annealing of the material in the atmosphere of gaseous CF4. Famous U.S. patent No. 4089937 published 16.05.1978 index IPC C01F 11/22, C01F 17/00, C01F 5/28, SW 9/08 "hot-pressed fluoride ion optical ceramic materials without absorption bands and methods of their manufacture". In this patent a method of hot pressing receive ceramics on the basis of fluorides of alkali, alkaline earth and rare earth elements, free from absorption bands belonging to the impurities CO2H2O, HE-. Receiving material are as follows. The raw material powder is placed in a mold for hot pressing and set in the oven, raise the temperature to 400-600°C and passed within a few hours through a system of gas-reducing agent (H2, Nsub> 2N2+H2N2+Not) or gaseous hydrogen fluoride (HF). Thus passed through the system the gas interacts with the raw powder fluoride, removing from its surface impurities. After processing gas to provide hot pressing the powder at temperatures of 400-800°C and the pressure 70-300 MPa. The above-described method are transparent optical ceramics for the entrance optics that are free from absorption bands of impurity bands HE, H2O and CO2 in the range of 1-7 μm. The disadvantages of similar concern: low process temperature and the absence of vacuum in the system that does not allow to obtain dense samples of optical ceramics, free from pores with high transmittance in the working range of 0.2 to 7 microns. In the method of obtaining laser fluoride ceramics according to the patent of Russian Federation №2321120 published 27.03.2008 IPC index H01S 3/16, as the source materials used powders fluoride and gidrohloridu alkali and alkaline earth metals and/or complex compounds of rare earth elements containing excess fluoride ion. Source powders are placed in the mold, which is established in the vacuum oven for pressing. In the furnace create a vacuum of 1 PA (7.5·10-3mm Hg), heat up and make the isothermal aging process, during which hydrohloride alkali and alkaline earth met low and/or complex compounds of rare earth elements disintegrate, forming the corresponding metal fluoride, hydrogen fluoride and ammonium fluoride (decomposition of complex compounds). The latter two compounds are fluorinating agents, cleansing the source powders from oxydiesel. In this way it is also proposed the implementation of fluoridation powder throughout the process of hot pressing. To do this, before heating in a vacuum furnace with the raw material powder sleuth of tetraploid carbon and do not stop the flow of gas throughout the process of obtaining ceramics. Thus, to prevent contamination of the synthesized material impurities from the used tooling. The processing efficiency of the active material of fluorine in the above method may not be high enough. When a source of active fluoride are used as starting powders, such as hydrohloride, the processing of the material in fluorinating environment is limited by the duration of isothermal soaking prior to extrusion. However, after decomposition hydrohloride at the stage subsequent hot pressing of the powder does not exclude the contamination of the compression of the material of unwanted impurities. In the case of processing of the compression of the powder gas CF4 time of contact with the fluorinating agent is limited by the duration of the process on acega pressing, which may be enough to remove from the material of all impurities. The method described above allows to obtain samples of fluoride ceramics with small indicators absorption in the region of 1 μm. For example, the absorption of ceramics based on calcium fluoride activated with ytterbium, at a wavelength of 1.064 μm is equal to 0.003 cm-1. However, this method of obtaining material provides high transparency fluoride ceramics in the UV, visible and IR region of the spectrum up to 1 μm, and the concentration of ytterbium in the divalent state reaches 20%, which reduces the efficiency of laser generation of ytterbium in the trivalent state. Known technical solution "Ceramic laser microstructured material with twin nanostructure and method of its manufacture" RF patent No. 2358045 published 27.02.2009 index IPC SW 28/00, 33/02, 29/12; H01S 3/16; VV 3/00). Here is a way to get laser ceramics on the basis of fluorides of alkali, alkaline earth and rare earth elements from the respective crystals, which consists in the following. The single crystal sample (fluoride of alkaline, alkaline earth or rare earth element or their solid solutions) is heated to temperatures from 2/3 of the melting point (MP.) to MP. and above (depending on the specific case) and by uniaxial with the Atiyah sample to deform relative change in linear dimension of the crystal (degree of deformation) 55-90%. Deformation can occur either in vacuum (10-2mm Hg) and a temperature below the melting temperature of the single crystal, or in the atmosphere gas of CF4and a temperature above the melting point of the material. In the process of deformation of the original single crystal is transformed into a material with a polycrystalline structure and a grain size structure of the crystallites 3-100 μm, while inside the grains is twinned structure with a characteristic size of 50-300 nm. This method allows you to get fluoride ceramics with improved compared with single crystals of mechanical characteristics and is capable of generating laser radiation. However, this method of obtaining material provides high transparency fluoride ceramics based on fluorides, alkaline earth and rare earth elements in the UV, visible and IR region of the spectrum, the concentration of ytterbium in the trivalent state does not exceed the threshold of 80%, and the overall efficiency of laser generation is low. The process gas environment CF4and a temperature above the melting point of the material leads to disruption of the structural homogeneity of the ceramic matrix, which makes it impossible to use such material as the optical medium. Unresolved at the time of development of the proposed technical solution problem affecting efficiency is the ability of the laser generation fluoride ceramics, is lack of cleanliness of the material associated with the admixture of divalent ytterbium. Partial transition of ytterbium in the bivalent condition associated with a deficiency of fluoride ion in a solid ceramic matrix. The decrease in the proportion of divalent ytterbium is a factor of increasing the purity of the laser material and has a positive impact, leading to an increase in the efficiency of laser generation. In Admixture of divalent ytterbium in laser crystals and ceramics Ca1-xRxF2+x" the authors of Caribina E.A., A.A. Demidenko, Guseva P.E., Krutova M.A., Mironov, I., Reiterova V.M., Smirnov A.N., Fedorov P.P., Chernova E.V., Osiko CENTURY (Proceedings of the XIV conference and VI of the school of young scientists of the Russian Academy of Sciences, Abstracts. Nizhny Novgorod, 2011, s) described trends in the development of the technique of obtaining laser ceramics of calcium fluoride doped with ytterbium fluoride, which says about the improvement of the properties of ceramics in the transition of Yb in the higher valence state, but no specific technology. Thus, in this work is the study of the state of the Yb, but obtaining on the net valence of 3+not studied, which, as shown in the proposed application, require the combined annealing, which involves the use of an oxidizing environment. The patent is F. No. 2358045 selected for the prototype of a new group of inventions: laser fluoride nanoceramics and how it was received. The task of the new technical solution is to obtain fluoride nanoceramics high purity by ensuring greater uniformity in the structure of the optical material. The problem is solved in the new material fluoride laser nanoceramics, presented in the form of a polycrystalline structure with a grain size of crystals of 3 to 100 microns with a nanostructure inside the grains, which comprises the activator ion rare earth element. Unlike the prototype, the activator is an ion of ytterbium with high valence. A new material, which eliminated the disadvantages of the prototype, since the laser ceramics based on calcium fluoride doped with ions of trivalent ytterbium, is a considerable interest for solid-state lasers with semiconductor pumping. The method of obtaining laser fluoride nanoceramics includes thermo-mechanical processing of the original crystalline material made of CaF2YbF3at a temperature of plastic deformation, receiving the workpiece in the form of polycrystalline microstructure of matter, characterized by a grain size of crystals of 3 to 100 μm and nanostructure inside the grains, which, unlike the prototype, thermomechanical processing of the original crystal m the material is carried out by annealing the workpiece in air at a temperature of not less than 0.5 of the melting temperature, the seal obtained preform is carried out in vacuum at a pressure of 1-3 mV/cm2before the end of the deformation process, after which the workpiece is annealed in an active medium fluorinating gas at a pressure of 800-1200 mm Hg As the source of crystalline material used fine powder that has undergone heat treatment in carbon tetrafluoride. As the source of crystalline material used molded preparation of the crystalline material obtained from a powder and heat in the carbon tetrafluoride. Annealing of polycrystalline material is carried out in fluorinating atmosphere at a partial pressure of 800-1200 mm Hg Manufacturing technology chosen empirically. Increasing the concentration of trivalent form ion of ytterbium by reducing the concentration of divalent form as possible by shifting the equilibrium of the reaction of formation YbF3from divalent form YbF2right by creating excess fluorinating agent, and the oxidation of Yb2+to the trivalent state by calcination of the precursor in an environment with an excess of oxidant, such as oxygen. Heat treatment of the precursor of Ca1-xYb3+xF2+xheld under pressure in contact with graphite or molybdenum alloy, i.e. in reducing conditions. If e is ω partially transition ion-activator of ytterbium in the divalent state by the reaction:
Divalent state of the ytterbium ion is manifested in the absorption spectra. Line of divalent ytterbium lie in the UV region and have peaks at wavelengths: 214, 227, 260, 271, 315 and 360 nm. In the spectra of most of the samples we recorded peaks at close values of the wavelengths: 228, 262, 274, 319 and 364 nm. Trivalent to ytterbium peaks correspond to 923, 945, 965 and 978 nm. The absorption coefficient is determined by the formula:
where: Ti- the value of the transmittance of the sample (in percent) at the point of maximum peak of the spectrum, d is the thickness of the sample in cm, Tmaxthe transmittance of the sample, expressed as a percentage, taking into account amendments, taking into account Fresnel losses of light on reflection. In accordance with equation (1) to suppress the reduction reaction of ytterbium should increase the partial vapor pressure of fluorine in the atmosphere. However, elemental fluorine is an extremely reactive chemical agent, and for practical work can be used only in extreme cases. However, there are fluorinating agents, inert under normal conditions, which can act as a source of fluorine at a temperature process. As the fluorinating agent used treatment in CF4. This reagent is used for the purification of crystals from oxygen-containing impurities. Were removed spectra of the samples of ceramics with a nominal composition of CaF2-3YbF3(mol. %)passed and not passed after synthesis processing in the atmosphere of CF4. The table presents the absorption coefficients (k), the relative values of the absorption coefficient (α) and the ratio of the relative absorption coefficients for divalent ytterbium (α1=ki/k978and for trivalent ytterbium (α2=ki/k978in samples fluoride nanoceramics before and after treatment fluorinating agent in the optimal mode. Presents the averaged values obtained p the results of many experiments, some of which are shown in the examples of implementation of the method of production of the material.
In the following table the importance of the ratio of the relative absorption coefficients α1/α2indicates a change of the ratio is osenia concentrations of divalent or trivalent ions - the proportion of divalent ytterbium after treatment of CF4significantly decreased. Simbathe decreasing values of k times after treatment fluorinating agent is also evidenced by a decrease in the proportion of divalent ytterbium. Translation in the trivalent state of the ytterbium ion is facilitated by the pre-stage oxidation of the precursor by calcination in air. This creates the conditions for the transition dwuhvalentny form of the trivalent ytterbium. Derived from the divalent forms of oxycoedone ytterbium (III) annealing at fluorinating environment translate in fluoride form, and excess fluoride ion in accordance with the foregoing, promotes the formation of more intense forms of fluoride, ytterbium - YbF3. Specific examples of the method for obtaining laser fluoride nanoceramics Example 1. A portion of 50 g of fine powder CaF2-3.0YbF3was placed in a cylindrical crucible with a diameter of the cavity is equal to that for the mold, and annealed in air for 24 hours at 700°C. the Obtained sintered sample was placed in a furnace for annealing, which is conducted at a temperature of 1300°C in an atmosphere of CF4at a pressure of 800 mm Hg for 10 hours. Briquette moved into the mold with a diameter of cavity 55 mm and subjected to uniaxial deformation in vacuum at a temperature of 150°C, applying a pressure of 2 mV/cm2within 30 minutes After it reached a pressure of 2 mV/cm2spent Isobaric-isothermal exposure for 60 minutes to give the workpiece a finite density. Thus obtained ceramic material is further subjected to annealing in an atmosphere gas of CF4at a pressure of 800 mm Hg and a temperature of 1300°C for 20 hours. The result was obtained ceramic material with high transmittance >90% in the spectral range from 0.4 to 7 μm, where there are no characteristic absorption bands ytterbium ion, and the average value of α1/α2=of 2.51. Example 2. The crystal structure of CaF2-3.0YbF3with a diameter of 25 mm and a height of 20 mm was annealed in air for 24 hours at 700°C. the resulting billet was placed in the mold with a diameter of cavity 55 mm and subjected to deformation at a temperature of 1150°C in vacuum with a force of 1 mV/cm2within 20 minutes to complete the separation. Then spent the Isobaric-isothermal exposure for 20 minutes for averaging the microstructure. Then, similarly to the previous example, has carried out the annealing of the material obtained in the gaseous environment of CF4at a pressure of 1000 mm Hg Synthesized polycrystal is formed of grains having a layered nanostructure, has high the th transparency and has a theoretical density value, and the average value of α1/α2=3.05. This sample is used to study the possibility of lasing of the laser radiation at wavelengths of 1.025 and 1.040 mm at the excitation radiation with a wavelength of 0.967 μm. When this generation efficiency was 45%. Example 3. A portion of 50 g of fine powder Caf2-5,0YbF3was placed in a cylindrical crucible with a diameter of the cavity is equal to that for the mold, and annealed in air for 24 hours at 700°C. the Obtained sintered sample was placed in a furnace for annealing in the atmosphere of CF4, which is held at a pressure of 1200 mm Hg and a temperature of 1300°C for 10 hours. Briquette moved into the mold with a diameter of cavity 55 mm and subjected to uniaxial deformation in vacuum at a temperature of 1150°C., applying a pressure of 2 mV/cm2within 30 minutes prior to the end of deformation. The degree of deformation amounted to a value of 170%. After it was reached the pressure of 2 mV/cm2spent Isobaric-isothermal exposure for 60 minutes. Thus obtained ceramic material was again subjected to annealing in an atmosphere gas of CF4at a pressure of 1200 mm Hg and a temperature of 1300°C for 20 hours. The result was obtained ceramic material with high transmittance >90% in the spectral range from 0.4 to 7 μm, the de no characteristic absorption band ion of ytterbium, and the average value of α1/α2=3.55. The obtained ceramics mode diode pump generates laser radiation with an efficiency of 51% in the region 1025 and 1040 nm and detects the high value of thermal conductivity of 4.7 W/MK, which allows you to use the nanoceramics blanks for the manufacture of small-sized solid-state active elements of high-power lasers. Scope - lasers for high energy physics, medicine, technology, materials processing, space goals, resource-saving technologies and many other areas of science and technology. 1. The method of obtaining laser fluoride nanoceramics, including thermo-mechanical processing of the original crystalline material made of CaF2-YbF3at a temperature of plastic deformation to obtain a workpiece in the form of polycrystalline microstructure of matter, characterized by a grain size of crystals of 3 to 100 μm and nanostructure inside the grains, wherein thermomechanical processing of the original crystalline material is carried out by annealing in air at a temperature of not less than 0.5 of the melting temperature, the seal obtained preform is carried out in vacuum at a pressure of 1-3 mV/cm2before the end of the deformation process, and then annealed in an act of the ate environment tetrafluoride carbon at a pressure of 800-1200 mm Hg 2. The method according to claim 1, characterized in that as the source of crystalline material used fine powder that has undergone heat treatment in carbon tetrafluoride. 3. The method according to claim 1, characterized in that as the source of crystalline material used molded preparation of the crystalline material obtained from a powder and heat in the carbon tetrafluoride. 4. Laser fluoride nanoceramics, obtained by the method according to claim 1.
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