52 results about "Barium fluoride" patented technology

The invention discloses bloom ultrahigh-carbon wear-resistant ball steel continuous casting covering slag and a preparation method thereof, and belongs to the technical field of steelmaking metallurgy auxiliary materials. The high-temperature-resistant electric smelting material is prepared from the following raw materials in parts by weight: 15-28 parts of wollastonite powder, 20-40 parts of an electric smelting pre-melting material, 3-6 parts of lithium metaborate, 2-8 parts of boron glass, 2-4 parts of sodium fluoride, 5-13 parts of sodium carbonate, 2-7 parts of barium fluoride, 7-11 parts of fluorite powder, 2-5 parts of electrode graphite, 2-5 parts of high-carbon amorphous graphite, 2-4 parts of N660 carbon black and 2-4 parts of dextrin. According to the mode, the casting liquid has relatively low viscosity, relatively low melting point and relatively high alkalinity, the lubrication of a casting blank is improved, the capability of absorbing floating inclusions in molten steel is improved, the occurrence rate of cracks and bleed-out on the surface of the casting blank is reduced, the surface and subcutaneous quality of the casting blank is improved, and the production efficiency of continuous casting is improved; the casting powder is particularly suitable for continuous casting production of bloom ultrahigh-carbon wear-resistant ball steel.

The invention provides high-transparency rare earth doped fluoride glass and a preparation method thereof, and belongs to the technical field of glass. The calcium fluoride ensures high transparency and chemical stability, the magnesium fluoride improves the ultraviolet transmittance and the mechanical strength, and the barium fluoride optimizes the melting fluidity and the rare earth doping uniformity; aluminum fluoride is added to inhibit crystallization and enhance uniformity, the rare earth element realizes optical function regulation and control, and ammonium fluoride provides a fluorine source and reduces impurities; in a preparation link, quick lime is dedusted and then reacts with pure water in proportion, impurities in a calcium nitrate solution are removed by hydrogen peroxide, uniform growth of calcium carbonate crystal nucleuses is controlled by ammonia water and carbon dioxide, and calcium fluoride is synthesized by hydrofluoric acid in proportion and dried at low temperature after plate-frame pressure filtration and purification; after the raw materials are refined through ball milling, the melting temperature is controlled in stages, impurities, reaction integrity and a microstructure are accurately controlled in the whole process, and finally the high-transparency functional glass is prepared.

The embodiment of the invention provides a friction material composition, a brake lining, a preparation method of the brake lining, a brake and a vehicle. The friction material composition comprises the following raw materials in parts by weight: 2-10 parts of a fluoride mixture, 8-15 parts of graphite, 8-12 parts of phenolic resin, 4-12 parts of a metal oxide, 15-40 parts of a fiber material and 20-40 parts of other fillers, wherein the fluoride mixture comprises at least two of calcium fluoride, barium fluoride, cerium fluoride, aluminum fluoride, magnesium fluoride, potassium fluoride, sodium fluoride, beryllium fluoride and manganese fluoride. The brake lining prepared from the friction material composition can solve the problems of high wear rate and heat fading at the same time, the service life of the brake lining is prolonged, and the braking effect is improved.

The invention discloses a low-distortion athermalization correctable short-wave infrared optical system and a lens, and belongs to the technical field of optics. According to the system, an optical lens is additionally arranged at the rear end to serve as a correction lens to achieve image correction in an external field environment; passive athermalization under wide-temperature and vacuum conditions is realized through focal power distribution and material matching of each optical lens; all the lenses are set to be spherical surfaces, so that the influence of aspheric surface processing errors on system index precision, processing cost and system installation and adjustment is avoided; the system adopts a positive-negative-positive-negative-negative five-lens focal power configuration. The positive-negative-positive-negative lenses are located at the front end, and the last negative lens is located at the rear end. The five lens materials are zinc sulfide, a chalcogenide material, single crystal barium fluoride, single crystal calcium fluoride and a chalcogenide material in sequence; the correction lens is located at the rear end of the last negative lens. The short-wave infrared optical system can solve the problems that an existing short-wave infrared optical system is large in imaging distortion, or athermalization is not achieved, or image correction under the external field application condition cannot be achieved.

The invention relates to the technical field of phosphorus chemical industry, in particular to a method for preparing monoammonium phosphate from raffinate acid, which comprises the following steps: S1) uniformly mixing the raffinate acid with concentrated sulfuric acid, concentrating, and performing solid-liquid separation to obtain a concentrated solution; s2) dropwise adding a solvent into the concentrated solution for primary solvent purification; the solvent components are limited; s3) standing and splitting the light and heavy mixed phase obtained by purifying the primary solvent to obtain an acid-containing solvent phase; s4) mixing the acid-containing solvent phase with barium fluoride, carrying out a reaction, and carrying out solid-liquid separation to obtain a secondary purified acid-containing solvent and purified slag; s5) carrying out vacuum distillation on the secondary purified acid-containing solvent, and recovering the solvent to obtain a distillation kettle residual liquid which is purified acid; and S6) diluting the purified acid, then mixing the diluted purified acid with an ammonia-containing alkaline substance, carrying out a neutralization reaction, filtering after the reaction, and drying and granulating a filter cake to obtain the fire-fighting grade monoammonium phosphate product. The method provided by the invention has the advantages of high impurity removal rate, high phosphorus yield and high added value of the product, and can be used for preparing fire-fighting grade monoammonium phosphate.

The invention belongs to the technical field of additive preparation, and particularly relates to an inner hole laser cladding composite powder material and a preparation method thereof. The invention provides an inner hole laser cladding composite powder material and a preparation method thereof in order to solve the problems that in the prior art, an inner hole laser cladding composite powder material is poor in uniformity and flowability and has limitation in the aspects of hardness, abrasion resistance and corrosion resistance. The material comprises tungsten carbide powder, NiCr alloy powder, silver and calcium fluoride-barium fluoride mixed crystals, mixed ball milling is conducted, ball milling is conducted again after presintering, then gas atomization treatment and laser pretreatment are conducted, and finally a nickel coating is formed on the surface of the powder through a chemical coating. The composite powder material has high hardness, high wear resistance, good corrosion resistance and high-temperature stability and is suitable for inner hole laser cladding, the service life of a workpiece is remarkably prolonged, and the performance of the workpiece is remarkably improved.

The invention discloses a continuous domain bound state sensor based on a composite prism all-dielectric metasurface, which is composed of periodically arranged unit structures, and each unit structure comprises a barium fluoride substrate layer and a group of silicon structure layers stacked on the barium fluoride substrate layer; the silicon structure layer comprises two first composite prisms arranged along a main diagonal line and two second composite prisms arranged along an auxiliary diagonal line, and the main diagonal line and the auxiliary diagonal line are in a crossed state; the tips of the two first composite prisms and the tips of the two second composite prisms are arranged in opposite directions, and the first composite prisms and the second composite prisms are of asymmetric structures; when polarized light is vertically incident, the resonance response of the ring dipole is excited, and two Fano formants are formed; the sensor has ultrahigh sensitivity and quality factor in a middle-infrared band, and can be applied to gas sensing and detection of various components of blood.

The invention discloses a low-oxygen-content barium fluoride continuous vacuum distillation purification device and method, and relates to the technical field of barium fluoride purification, the device comprises a vacuum tower, the top surface of the vacuum tower is hermetically connected with a sealing cover, the center position of the top surface of the sealing cover is provided with a vacuumizing mechanism, and the inner side of the sealing cover is provided with a continuous feeding mechanism; a heating mechanism is arranged in the middle of the inner cavity of the vacuum tower; the vacuum pumping mechanism is arranged and used for controlling the continuous feeding mechanism and the heating mechanism while keeping the vacuum degree of the vacuum tower, so that the continuous feeding mechanism controls the continuous feeding speed of barium fluoride based on the barium fluoride distillation and purification speed of the heating mechanism, and the feeding accuracy of barium fluoride is guaranteed.

The invention discloses a hydrogenation catalyst which is a supported catalyst, the catalyst is in a particle shape, the particles are porous metal fluoride embedded with palladium element, the porous metal fluoride is selected from one or more of aluminum fluoride, chromium fluoride, magnesium fluoride, barium fluoride, calcium fluoride, aluminum fluoride oxide and chromium fluoride oxide, and the palladium element is one or more of aluminum fluoride, chromium fluoride, magnesium fluoride, barium fluoride, calcium fluoride, aluminum fluoride oxide and chromium fluoride oxide. The invention also provides a preparation method of the catalyst. According to the catalyst prepared by the method, the synthesis yield and conversion rate are high in the process of synthesizing HFC-236ea from C3F6 and synthesizing HFC-245eb from HFO-1225ye, and the product purity and yield are excellent. According to the catalyst used in the invention, aluminum oxyfluoride is used as a carrier of metal palladium, Pd particles and a carrier interface are tightly combined, and a falling sign does not appear, so that the Pd component is excellent in dispersity, and the reaction rate and the raw material conversion rate are favorably improved.

The invention discloses an infrared transparent printing ink, which is composed of 42-60% of a polyurethane-acrylic acid composite emulsion, 23-35% of an infrared transparent filler, 5-15% of a microencapsulated organic color paste, and 4-8% of an auxiliary agent. The innovation points are as follows: cubic crystal nano barium fluoride and silane coupling agent modified nano zinc sulfide are compounded according to the ratio of 1: (1-5), the refractive index is matched with that of a resin matrix, and an infrared transmission window of 800-1500nm is broadened synergistically; the organic color paste containing sulfonic groups is encapsulated by the polyvinyl alcohol microcapsules, so that visible light color development is realized, infrared absorption is reduced, and the light transmittance is greater than 90%. The preparation process comprises the steps of nano ZnS surface modification, high-pressure homogeneous microcapsule granulation, zirconium bead sanding dispersion, vacuum defoaming and the like, solves the problem of compatibility of color gamut display and infrared light transmission, and is suitable for infrared detection application of packaging labels.

This invention discloses a mid-to-far-infrared ultra-wideband neutral beamsplitter based on KBr crystal, its fabrication method, and its applications, relating to the field of optical thin film technology. The KBr crystal-based mid-to-far-infrared ultra-wideband neutral beamsplitter includes a KBr crystal substrate; a front surface adhesive layer disposed on the front surface of the KBr crystal substrate; an ultra-wideband neutral beam splitter disposed on the surface of the front surface adhesive layer; a rear surface adhesive layer disposed on the rear surface of the KBr crystal substrate; and an ultra-wideband protective film disposed on the surface of the rear surface adhesive layer. The front and rear surface adhesive layers are both magnesium fluoride thin films; the ultra-wideband neutral beam splitter has a multilayer dielectric film structure; and the ultra-wideband protective film is a barium fluoride thin film. This invention innovatively introduces a double-sided composite thin film structure of "front surface adhesive layer + beam splitter system" and "rear surface adhesive layer + protective layer".

The present invention provides applications of rare earth ion-doped alkaline earth metal fluoride crystals, including applications in solid-state lasers, laser imaging, environmental detection, satellite guidance, information storage, or underwater detection. The rare earth ion-doped alkaline earth metal fluoride comprises a matrix crystal and dysprosium ions or Dy / RE co-doped ions doped in the cation lattice of the matrix crystal, wherein the RE comprises at least one of Tm, Pr, and Sm; the matrix crystal comprises calcium strontium fluoride or barium fluoride crystals. The crystals employed in the present invention have low phonon energy and high fluorescence quantum efficiency. The introduction of calcium improves the stability of the crystals; the Dy / RE co-doping enhances energy level transfer. The crystals employed in the present invention have an absorption wavelength range of 250 to 600 nm. Upon excitation with ultraviolet or blue light, they can produce a broad emission spectrum spanning the violet to orange wavelength range, making them ideal working materials for direct pumping of semiconductor lasers.

The invention belongs to the field of rare earth afterglow luminescent materials. The invention discloses a high-brightness divalent rare earth afterglow material. The molecular formula of the high-brightness divalent rare earth afterglow material is BaFCl: Gd / Li / Sm. The preparation method sequentially comprises the following steps: uniformly mixing and grinding barium fluoride, barium chloride, gadolinium chloride, samarium chloride and lithium chloride in proportion, carrying out high-temperature reaction in a tubular furnace, and carrying out heat preservation in a drying oven to obtain a product. The product has the characteristics that the product has very strong afterglow performance under X-ray excitation, the afterglow luminescence brightness value can reach 4.53 cd m <-2 >, the afterglow duration is longer than 100 hours, and the product has a very good application prospect in the field of delayed X-ray imaging.

The invention belongs to the technical field of semiconductor material preparation, and relates to a multi-element oxide film and a preparation method and application thereof. The technical problem that in the prior art, large-area uniform preparation of a multi-element oxide film is difficult is solved. The invention provides a preparation method of a multi-element oxide thin film, which adopts molecular beam epitaxy co-evaporation preparation and comprises the following steps: placing a substrate in a molecular beam epitaxy co-evaporation preparation cavity, and vacuumizing the cavity; performing YSZ buffer layer deposition and CeO2 buffer layer deposition on the substrate in the cavity from bottom to top in sequence, and controlling automatic evaporation of electron beams through a film thickness gauge to obtain a substrate containing a buffer layer; yttrium, copper and barium fluoride are co-evaporated on a substrate containing a buffer layer to perform YBCO film deposition, a Y evaporation source, a Cu evaporation source and a Ba evaporation source are controlled by a film thickness gauge to perform co-evaporation, and a multi-element oxide film with large area and good uniformity is obtained. The invention further provides the multi-element oxide thin film and application thereof.

The application discloses an active carbon / fluoride ion conductor composite electrode and a preparation method thereof. The method comprises the following steps: 1) taking active carbon as raw material to prepare a column-shaped carbon electrode blank; 2) taking lanthanum fluoride and barium fluoride according to a proportion, uniformly mixing, and then pre-sintering under high-temperature conditions, crushing, and obtaining fluoride ion conductor powder with a chemical formula of La 1‑ x Ba x F 3‑x , x=0.05-0.1; 3) adding a sintering aid into the obtained powder, uniformly mixing, then adjusting into a paste shape with a polyvinyl alcohol aqueous solution, and coating the paste on the inner side of the carbon electrode blank to obtain an active carbon / fluoride ion conductor laminated body; and 4) sintering the obtained active carbon / fluoride ion conductor laminated body under high-temperature conditions, and the composite electrode is obtained. The composite electrode prepared by the method has good fluoride ion conduction capacity, can effectively improve the defluorination efficiency of the electrode, and realizes high-efficiency fluoride ion removal.

The application discloses fine-grained steel SAW fluorine alkali type sintered flux and application, including barium fluoride 28-33%, aluminum ash powder 10-12%, dolomite 5-7%, pre-melted slag powder 25-27%, fluorocarbon cerium ore 2-3%, titanium boron iron 1.5-2.5%, kaolin 6-8%, magnesite 4-6%, silicon calcium aluminum powder 10-13% by weight percentage. The application can meet the submerged arc welding requirement of 65kg grade structural steel in most cases, has good welding process and mechanical properties of post-welding deposited metal, is widely applied in the construction, machinery and other industries, and greatly improves the production and life efficiency of people.

This invention discloses a narrowband polarization metasurface for suppressing long-wave infrared angular dispersion and its fabrication method, relating to the field of optical component technology. Addressing the problems of difficult fabrication and strong angular dispersion inherent in existing polarizers, the metasurface of this invention comprises a barium fluoride substrate and a double-layer composite grating structure disposed on its surface. The composite grating includes a bottom arsenic selenide grating and a top metal layer. By limiting the period of the composite grating to 5.5-6.25 micrometers and the width of a single double-layer grating structure to 4.5-5.5 micrometers, the downward-leaking guided modes and Fabry-Perot cavity modes within the structure undergo strong compression in momentum space, resulting in band folding and anti-crossing flat-band effects. This invention not only relaxes the feature size to the micrometer level, significantly reducing fabrication difficulty, but also fundamentally suppresses the strong angular dispersion of plasmon resonance in narrowband, achieving a high polarization extinction ratio under large angle tolerance and greatly reducing the collimation requirements of practical optical paths.

Siloxane-based coating compositions that may be applied to the surface of a substrate, such as an article of cookware or bakeware, to form a durable non-stick coating with extended easy to clean properties. The coating compositions may include a siloxane resin, an organic oil, and a fluoride component such as particles of calcium fluoride (CaF2), magnesium fluoride (MgF2), strontium fluoride (SrF2), and / or barium fluoride (BaF2).

The electron tube of the present invention comprises: a shell, the interior of which is kept in vacuum and has a window for transmitting electromagnetic waves; an electron emission unit, which is arranged in the shell and has a metasurface for emitting electrons in response to the incidence of the electromagnetic waves; an electron multiplication unit, which is arranged in the shell and multiplies the electrons emitted from the electron emission unit, and an electron collection unit, which is arranged in the shell and collects the electrons multiplied by the electron multiplication unit. The window comprises at least one selected from quartz, silicon, germanium, sapphire, zinc selenide, zinc sulfide, magnesium fluoride, lithium fluoride, barium fluoride, calcium fluoride, magnesium oxide and calcium carbonate.

The invention discloses an electrolyte for low-temperature aluminum electrolysis and a preparation method thereof, and belongs to the technical field of electrolytes for aluminum electrolysis. The technical problems of high electrolysis temperature and large volatilization caused by high primary crystal temperature of the existing electrolyte for aluminum electrolysis are solved. The invention provides an electrolyte for low-temperature aluminum electrolysis and a preparation method thereof, and the electrolyte for low-temperature aluminum electrolysis comprises the following components in percentage by weight: 15 to 25 percent of sodium fluoride NaF, 14 to 29 percent of potassium fluoride KF, 0.1 to 4 percent of barium fluoride BaF2, 0.5 to 5 percent of aluminum oxide Al2O3, and the balance of AlF3 and inevitable impurities. According to the electrolyte for low-temperature aluminum electrolysis, the primary crystal temperature is reduced by adjusting an electrolyte system, so that the electrolysis temperature is reduced, and fluoride volatilization is reduced.

The invention relates to an alkaline flux-cored wire for welding oil and gas pipelines and a preparation method of the alkaline flux-cored wire, and belongs to the technical field of preparation of high-strength and high-toughness welding materials. The flux-cored wire is prepared from a steel belt and powder through steel belt rolling, powder filling, welding wire drawing and coil dividing. By controlling the components of the flux powder of the flux-cored wire, it is determined that the component system of the flux powder is composed of BF-Fe2O3-Al2O3-NiO-MgO-MnO, the component system is a main barium fluoride slag system supplemented with aluminum oxide, magnesium oxide strong deoxidizers and the like, and under the protection of carbon dioxide, the slag system is stable in electric arc, small in splashing, high in porosity resistance and good in fusion performance; the mechanical property of a ring welding joint welded by the obtained welding wire, the mechanical property of deposited metal and the diffusible hydrogen content meet the GB / T36233-2018 requirements.

The invention belongs to the technical field of PTFE material preparation, and particularly relates to a preparation method of a modified PTFE wear-resistant material. The preparation method comprises the following steps: (1) preparing modified chrome corundum micro powder; (2) preparing modified molybdenum carbide; (3) preparing modified barium fluoride; and (4) preparing the modified PTFE wear-resistant material. According to the preparation method of the modified PTFE wear-resistant material, PTFE resin is used as a main raw material, modified chrome corundum micro-powder, modified molybdenum carbide and modified barium fluoride are added to serve as filler, and the wear-resistant performance of the modified PTFE wear-resistant material is improved through the high-hardness bearing and micro-cutting blocking effects of the modified chrome corundum micro-powder. The micro-polishing effect of the modified molybdenum carbide and the interface toughening and low-shearing lubricating film effect of the modified barium fluoride are used for improving the wear resistance of the PTFE material and ensuring the mechanical property of the PTFE material.

To provide a transparent material having similar optical transmissivity to that of monocrystalline of barium fluoride.SOLUTION: Barium fluoride sintered compact has transmissivity of 85% or more to light of 550 nm wavelength and transmissivity of 80% or more to light of a range of 340 nm or longer and 2000 nm or shorter and to light of a range of 4.5 μm or longer and 10.5 μm or shorter.SELECTED DRAWING: Figure 6

The invention provides a zirconium-aluminum non-reaction drainage agent and a preparation method thereof, and belongs to the technical field of metallurgical auxiliary materials. The zirconium-aluminum non-reaction drainage agent is prepared from the following raw materials in parts by weight: 10 to 70 parts of fused alumina zirconia, 10 to 46 parts of white corundum, 18 to 78 parts of sintered zirconium dioxide, 1 to 5 parts of barium fluoride and 1 to 6 parts of graphite colloidal dispersion liquid. The drainage agent is low in silicon and free of chromium, does not react with alloy elements such as aluminum, titanium and manganese, is high in refractoriness and permeation resistance, and can guarantee good self-opening rate and molten steel purity.

The invention belongs to the technical field of plasma technology, and relates to a method for preparing spherical fluoride eutectic based on plasma technology. The invention provides a method for preparing spherical fluoride eutectic based on a plasma technology, which comprises the following steps: mixing calcium fluoride and barium fluoride, and carrying out ball milling to obtain precursor slurry; carrying out spray drying granulation on the precursor slurry to obtain precursor powder; and feeding the precursor powder into a direct-current plasma environment to prepare the spherical fluoride eutectic. According to the preparation method disclosed by the invention, the precursor slurry is prepared by ball milling, and the spray drying granulation is used for replacing the vacuum sintering in the preparation of the spherical fluoride eutectic by a plasma technology, so that the technical problem of high energy consumption caused by using the vacuum sintering when the spherical fluoride eutectic is prepared by the plasma technology is solved; and the product quality is improved.

The invention relates to the technical field of fluoride catalysts, and particularly discloses a fluoride catalyst for catalyzing CFC-113a to synthesize CFC-1316mxx and a preparation method of the fluoride catalyst. The fluoride catalyst is prepared from a catalyst precursor, and the catalyst precursor comprises a transition metal salt and a fluoride carrier MFx, wherein the transition metal salt is selected from any one or more of ruthenium salt, rhodium salt, palladium salt, nickel salt and copper salt; the fluoride carrier MFx is selected from any one or more of sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride and aluminum fluoride. When the fluoride-based catalyst is used for catalyzing CFC-113a to synthesize CFC-1316mxx through hydrogenation coupling, the CFC-1316mxx selectivity and the CFC-113a conversion rate are remarkably high, and finally, the yield of the target product CFC-1316mxx reaches up to 91.98%.

The invention discloses a preparation method of high-purity electronic-grade hydrofluoric acid, and particularly relates to a preparation method of electronic-grade hydrofluoric acid, which comprises the following steps: in the presence of villiaumite, carrying out impurity removal reaction on industrial hydrogen fluoride, and then purifying the obtained mixed solution to obtain the electronic-grade hydrofluoric acid, the villiaumite comprises cobalt trifluoride and barium fluoride. The preparation method is mild in reaction, low in production energy consumption, easy to operate and control and capable of solving the problem of pollution caused by oxidant pulverization. And the adopted villiaumite can be reused after being fluorinated for multiple times, so that the use is safe, and the purification effect is good.

The invention belongs to the technical field of welding materials, and particularly provides a nickel-based welding material welding flux which comprises, by mass, 20%-40% of fluorite, 10%-20% of quartz, 15%-30% of aluminum oxide, 5%-15% of magnesium oxide, 2%-7% of sodium fluoride, 5%-15% of calcium oxide, 1%-5% of barium fluoride and 3%-9% of silicon-manganese alloy. The welding flux for the nickel-based welding material is low-hydrogen fluorine-alkali type welding flux, the welding process performance is excellent, electric arcs are stable during welding, after welding is completed, welding slag and weld metal are automatically separated, upwarp and fall off, a weld joint is attractive in forming, the surface is bright, welding lines are fine, and the welding flux is suitable for alternating-current and direct-current flat welding and horizontal welding; and a weld joint has good ultralow-temperature (-196 DEG C) impact toughness, low cold and hot crack sensitivity, high yield strength and tensile strength, high ductility and excellent welding process performance.

The application belongs to the technical field of PTFE material preparation, and particularly relates to a preparation method of modified PTFE wear-resistant material. The preparation method comprises the following steps: (1) preparation of modified chromium corundum micro powder; (2) preparation of modified molybdenum carbide; (3) preparation of modified barium fluoride; and (4) preparation of modified PTFE wear-resistant material. According to the preparation method of the modified PTFE wear-resistant material, PTFE resin is used as a main raw material, and modified chromium corundum micro powder, modified molybdenum carbide and modified barium fluoride are used as fillers. Through the high-hardness bearing and micro-cutting blocking effect of the modified chromium corundum micro powder, the micro-polishing effect of the modified molybdenum carbide and the interface toughening and low-shear lubricating film effect of the modified barium fluoride, the wear resistance of the PTFE material is improved, and the mechanical properties of the PTFE material are ensured.

The invention provides a barium yttrium fluoride optical thin film, a preparation method thereof and a middle and far infrared optical structure. The preparation method of the yttrium barium fluoride optical thin film comprises the following steps that an optical substrate and a yttrium barium fluoride compound are provided, the yttrium barium fluoride compound is a composite material which is obtained through quenching treatment after yttrium fluoride and barium fluoride are subjected to a high-temperature solid-phase reaction, and the grain size of the yttrium barium fluoride compound is in the submicron level; the metastable state crystal phase structure is a cubic phase with an Fm-3m space group and / or a tetragonal phase with a lattice distortion P4 / nmm space group; the optical substrate is heated to 150 DEG C to 200 DEG C; and depositing the barium yttrium fluoride optical thin film on an optical substrate by using an electron gun evaporation method and taking the barium yttrium fluoride compound as an evaporation source. The yttrium barium fluoride optical thin film can still keep a compact and continuous structure morphology without microcrack distribution under the condition that the single-layer film thickness reaches 2-6 microns, and has very good optical transparency, thermal stability and mechanical integrity.