80 results about "Solid state reaction method" patented technology

The invention discloses a series of alkali metal borate compounds and alkali metal borate crystals as well as a preparation method and application thereof, and belongs to the technical field of photoelectric functional crystal materials. The chemical general formula of the series of compounds and crystals thereof is A3RE (B3O6) 2, wherein A is K, Rb, Cs or NH4; rE = Sc and Y, the molecular weight is 355.93-744.48, the series of crystals belong to a trigonal system, the space group is P321, the cell parameters a = b = 10.5237 (13)-135237 (13), and # imgabs0 # Z = 3. The series of alkali metal borate compounds are synthesized by adopting a solid-phase reaction method or a hydrothermal method, and the series of crystals grow by adopting a high-temperature melt method or a hydrothermal method or a solution method. The series of materials can be used for manufacturing second harmonic generators, upper and lower frequency converters, optical parametric oscillators, polarizing prisms and the like.

The invention relates to a purple-light-excited blue-light fluorescent material for a sunlight-like LED (light-emitting diode) as well as a preparation method and application of the blue-light fluorescent material. The chemical expression of the fluorescent material is Ca2LuZr2Al1. 5Ga1. 5O12: xCe < 3 + >, wherein x is more than or equal to 0.02 and less than or equal to 0.07. The blue light fluorescent material for the purple light excitation type sunlight LED is a brand new and unreported purple light excitation Ce < 3 + > doped oxide blue light emission fluorescent material, the fluorescent powder has a wide excitation band, the effective absorption range covers 300-450 nm, the fluorescent powder can be excited by purple light, and blue light with the central wavelength being 485 nm is emitted. The fluorescent powder has the advantage of stable physical and chemical properties, can be prepared by adopting a conventional solid-phase reaction method, has the characteristics of simple preparation process and facilitation of industrial production, and can be used as a good candidate material for wide application of a next-generation full-spectrum illumination white light LED (light-emitting diode). The fluorescent powder can be completely and well matched with the existing purple light chip, meets the commercial market requirements, and is suitable for application of white light LEDs, sunlight-like LEDs, full-spectrum LEDs and the like.

The invention belongs to the field of inorganic nonmetals, discloses a wide-temperature-range inorganic negative thermal expansion material and a synthesis method thereof, and requests to protect application of a Mn2V2O7 material as a negative thermal expansion material. The Mn2V2O7 material can be prepared on the basis of a solid-phase reaction method. The negative thermal expansion performance of the Mn2V2O7 material is disclosed for the first time, the negative thermal expansion temperature range is large and is 69-497 DEG C, the negative thermal expansion coefficient reaches-4 * 10 <-6 > DEG C <-1 >, and the Mn2V2O7 material is a wide-temperature-range inorganic negative thermal expansion material. The Mn2V2O7 material does not contain Hf, Dy, Lu, W and other rare metal elements, has a large negative thermal expansion temperature interval, and can be compounded with organic matters, metals, ceramics and the like to adjust the thermal expansion coefficient of the Mn2V2O7 material.

The invention relates to an ultraviolet / purple light excited blue fluorescent material as well as a preparation method and application thereof. The Eu < 2 + > doped oxide-based blue fluorescent material has a chemical expression of BaHfSi2O7: xEu < 2 + >, and x is more than or equal to 0.003 and less than or equal to 0.02. Compared with the prior art, the purple-light-excited blue fluorescent material provided by the invention is brand-new and unreported ultraviolet-excited Eu < 2 + >-doped oxide-based 472nm blue-light-emitting fluorescent powder, the fluorescent powder has a wide excitation band, the excitation spectrum range covers 200-450nm, the emission spectrum range covers 390-680nm, and the fluorescent material has a good fluorescent effect under the excitation of 304nm near ultraviolet light. The blue light with the central wavelength of 472nm is emitted, and meanwhile, the blue light emitting material has excellent stability and luminous efficiency. The fluorescent powder can be prepared by adopting a conventional solid-phase reaction method, has the characteristics of simple preparation process and facilitation of industrial production, can be combined with a near ultraviolet chip to generate white light, can be used as a good candidate material for wide application of a white light LED, and can meet the urgent demand of a current healthy illumination LED light source.

The invention provides a method for growing a 1T-TaS2 single crystal by using iodine as a transport agent through a vapor transport method, and belongs to the field of single crystal preparation. The method comprises the following steps: (1) preparing a TaS2 polycrystal through repeated sintering by a solid-phase reaction method, and (2) uniformly mixing the TaS2 polycrystal with a transport agent I2, and preparing the 1T-TaS2 single crystal by a chemical vapor transport method. The principle of the method is that a solid raw material reacts with a transport agent in a high-temperature region (source region) to generate a gaseous intermediate product. The gas-phase component circulates in the tube through concentration gradient to realize continuous transportation, and finally in a low-temperature region (growth region), the gaseous compound moves in a balanced manner due to temperature difference to generate reverse reaction, and target single crystals are separated out. The 1T-TaS2 single crystal grown by the method has high quality, and is suitable for further research on physical properties such as charge density wave and the like of the 1T-TaS2 single crystal.

The invention discloses a monovalent alkali metal ion doped iron-based perovskite type ceramic membrane as well as a preparation method and application thereof, and belongs to the technical field of mixed conductor oxygen permeation ceramic membrane materials. The method comprises the following steps: (1) synthesizing layered rock salt oxide M1 by adopting an EDTA-CA (Ethylene Diamine Tetraacetic Acid-Carboxylic Acid) sol-gel method; (2) mixing the M1 with other metal carbonate or oxide according to the stoichiometric ratio of the target perovskite oxide M2, and preparing a solid precursor M1 + M2 through a solid-phase reaction method; and (3) sintering the precursor into a compact ceramic membrane by using a static pressure-roasting method. According to the invention, the problem that monovalent alkali metal ions are easy to volatilize in a high-temperature solid-phase reaction is effectively solved through a process of stabilizing the alkali metal at a low temperature and then forming a film at a high temperature, and the monovalent alkali metal ions are successfully doped into iron-based perovskite crystal lattices. The prepared ceramic membrane has the advantages that the oxygen permeation flux is obviously improved while the good structural stability is maintained, and the ceramic membrane is particularly suitable for oxygen separation in an oxygen-enriched combustion process.

The application provides high-curie-temperature low-resistance lead-free thermosensitive ceramic and a preparation method thereof, and belongs to the technical field of electronic ceramic elements. 1‑x‑y La x (Bi 0.5 Na 0.5 ) y )(Ti 0.9996 Mn 0.0004 )O3; wherein the value range of x is 0.001<=x<=0.004, and the value range of y is 0.001<=y<=0.0075. The preparation method comprises the following steps: mixing (Bi 0.5 Na 0.5 )TiO3 powder synthesized by two-stage heating hydrothermal method, (Ba 1‑x La x )TiO3 powder synthesized by solid-phase reaction method, Mn(NO3)2 aqueous solution and sintering auxiliary agent AST powder, then performing granulation, molding, glue removal and sintering. The barium titanate-based thermosensitive ceramic prepared by the method has extremely low room temperature resistivity and relatively high curie temperature.

The invention relates to a cobalt-free ultra-high nickel positive electrode material and a preparation method and application thereof, the preparation method comprises the following steps: ball-milling and mixing a nickel source, a lithium source and a dopant to obtain powder, and drying and sintering the obtained powder to obtain the cobalt-free ultra-high nickel positive electrode material, the doping agent comprises an aluminum-containing doping agent and a manganese-containing doping agent; the nickel source, the lithium source and the doping agent are mixed according to the molar ratio of the nickel element to the lithium element to the total doping element being (0.90-0.98): (1.03-1.06): (0.02-0.10). The Al and Mn elements are uniformly doped in the positive electrode material substrate through a solid-phase reaction method, the material performance is synergistically improved by utilizing the unique action mechanism of the doped elements, the electrochemical performance is synergistically improved on the premise of not depending on the cobalt element, and high initial discharge capacity, cycling stability and rate capability are kept in a wide voltage interval; and excellent capacity retention capability is shown in a wide multiplying power range.

The invention discloses an X8R type capacitor dielectric ceramic material and a preparation method thereof. The ceramic material comprises the following components: (1-x) BaTiO3-xBi [(Mg2 / 3Ta1 / 3) 1-0.015 x Nb 0.015 x] O < 3 + > 0.015 x, MnO2 and ZnO, the preparation method comprises the following steps: taking BaCO3, Bi2O3, TiO2, MgO, Ta2O5 and Nb2O5 as raw materials, mixing, drying and calcining through a solid-phase reaction method to obtain main crystalline phase powder, then mixing the main crystalline phase powder with MnO2 and ZnO, and carrying out ball milling, molding and sintering to obtain the ceramic material. The ceramic material provided by the invention has a fine-grain compact structure, and not only has a relatively high dielectric constant and extremely low dielectric loss, but also has a dielectric constant temperature change rate meeting the EIA X8R standard.

The present invention relates to a low-dielectric and low-loss magnesium silicate system microwave dielectric ceramic and a low-temperature preparation method thereof. The present invention uses Mg2SiO4 ceramic as a matrix and adopts Mg 2+ Mg was synthesized by the conventional solid phase reaction method using non-stoichiometric modification, CaTiO3 to adjust the temperature stability and LiF to reduce the sintering temperature. 2.1 SiO 4.1 ‑xCaTiO3‑yLiF multiphase composite microwave dielectric ceramics, wherein x=0.09~0.13,y=0.05~0.25. The multiphase composite makes the prepared Mg 2.1 SiO 4.1 ‑xCaTiO3‑yLiF has a low dielectric constant, low dielectric loss, and a near-zero resonant frequency temperature coefficient, and reduces the sintering temperature of ceramic samples. This invention could provide an alternative material for the preparation of high-frequency communication components using LTCC technology, and has broad application prospects.

The application provides a preparation method and device of high-purity zinc arsenide by multiphase reduction-melt alloying, and belongs to the technical field of inorganic compound synthesis. The method uses arsenic trichloride as an arsenic source, volatilizes the arsenic trichloride by precise temperature control, and transports AsCl3 vapor to a reactor containing high-purity liquid zinc by using high-purity inert gas as a carrier gas; at a set reaction temperature, the liquid zinc reduces the AsCl3 gas phase to generate elemental arsenic, and the elemental arsenic immediately reacts with zinc to generate zinc arsenide Zn3As2 in situ; the by-product zinc chloride ZnCl2 escapes in a gaseous form and is collected by a condensation system, and the zinc arsenide is suspended on the surface of the zinc melt due to the lower density than the liquid zinc, so that continuous or batch separation and collection can be realized. The application has the advantages of simple process, high reaction efficiency and high product purity, avoids problems such as uneven components and introduction of impurities in the traditional solid-phase reaction method, and is suitable for large-scale production of semiconductor-grade zinc arsenide materials.

The invention discloses a low-loss high-tunability BZT laminated dielectric film and a preparation method thereof, the laminated film comprises a substrate, a BZT film layer and a zinc niobate-based microwave dielectric ceramic film layer, and the chemical general formula of the zinc niobate film layer is Zn [(Ge0. 5Mo0. 5) xNb1-x] 2O6. A ceramic target material is synthesized by adopting a solid-phase reaction method, and thin film layers are sequentially deposited through a magnetron sputtering technology to construct a heterostructure. The high dielectric constant of BZT and the low loss characteristic of zinc niobate are combined, the frequency characteristic is remarkably improved, the dielectric loss is effectively reduced while the high tunability is kept, and the high-quality FOM is obtained and reaches 36.77. The film is excellent in performance and controllable in process, and has important application value in microwave communication devices such as tunable filters and phased array radars.

The invention provides a crack-free lithium niobate film based on a Si substrate and a growth method and application thereof, and belongs to the field of ferroelectric film growth methods. According to the crack-free lithium niobate thin film based on the Si substrate, the substrate is selected from a Si substrate, and a target material is selected from congruent lithium niobate ceramic doped with 2.0 mol%-5.0 mol% of erbium and congruent lithium niobate ceramic doped with 5.0 mol% of iron prepared by a solid-phase reaction method, or is selected from congruent lithium niobate crystal doped with 2.0 mol% of erbium and congruent lithium niobate crystal doped with 5.0 mol% of iron prepared by a Czochralski method, or is selected from congruent lithium niobate crystal doped with 5.0 mol% of erbium and congruent lithium niobate crystal doped with 5.0 mol% of iron prepared by a Czochralski method. The lithium niobate thin film shows a lithium niobate (006) characteristic diffraction peak and a lithium-deficient phase LiNb3O8 (-602) characteristic diffraction peak, the surface of the lithium niobate thin film is flat, smooth and crack-free, the problem of surface cracking of a Si-based lithium niobate thin film for a long time is solved, and the lithium niobate thin film can be used for preparing micro-cavities, electro-optical modulators, photoelectric detectors, super-surface micro-nano devices and the like and has wide application prospects. And a foundation is laid for manufacturing and researching an integrated device on a lithium niobate film sheet.

The application discloses a preparation method for improving stability of a proton conductor electrolyte in carbon dioxide, relates to the technical field of solid oxide batteries and solid oxide electrolysis cells, and is characterized by the following steps: through a nano-additive surface modification method, a nano-structure additive of an alkaline earth metal oxide, or a transition metal oxide, or a VA main group metal oxide is prepared on the surface of a barium cerate and a barium zirconate series electrolyte obtained through a solid phase reaction method by using a vacuum impregnation method, and an alkaline proton conductor electrolyte with a surface modification additive is obtained. The alkaline proton conductor electrolyte with the surface modification nano-structure additive obtained by the application can be applied to a proton type carbon hydrogen ceramic membrane fuel cell or high-temperature electrolysis carbon dioxide, so that the stability of the electrolyte can be effectively enhanced, and ohmic loss can be reduced, thereby greatly improving the performance and stability of the solid oxide fuel cell and the electrolysis cell under a carbon dioxide atmosphere.

The application belongs to the technical field of thermoelectric device preparation and connectors, and aims to solve the problem of Te 0.985 Sb 0.015 During the connection of thermoelectric materials and Ni electrodes, a large number of aggregated pores and segregation of doped elements Sb are generated at the interface, which seriously weakens the electrical transport performance and thermal stability at the interface. A method for improving the performance and thermal stability of Te-based thermoelectric arms by using topological dense packing is provided. A topological dense packing NiTe 2‑x , 0≤ x ≤0.9 is synthesized by a solid phase reaction method, which is introduced into the Ni and Te 0.985 Sb 0.015 between them to form a Ni / NiTe 2‑x / Te 0.985 Sb 0.015 / NiTe 2‑x / Ni gradient connection structure. The problem of a large number of aggregated pores and segregation of doped elements Sb due to the severe diffusion of Ni into Te 0.985 Sb 0.015 and reaction at the interface is successfully eliminated, and the performance and service life of the thermoelectric connector are improved.

The present invention belongs to the technical field of electronic materials, specifically a Mg-Ti-O-based high-Q high thermal conductivity microwave dielectric ceramic material and a preparation method thereof. The ceramic material of the present invention adopts a solid-phase reaction method, and generates a subcrystalline phase MgTiO3 with a high Q value and a high thermal conductivity by doping Mg2TiO4 with TiO2. The microstructure and density of the overall material are improved by the composite ceramic system, thereby improving the thermal conductivity and Q×f value of the ceramic material; the (1-y)Mg2TiO4+yMgTiO3 ceramic material prepared by the present invention, 0<y<0.5, has a thermal conductivity of 8.0~10.5W / (m·K), a Q×f value of 100000~150000GHz, and a relative dielectric constant of 14~16. The Mg-Ti-O-based high-Q high thermal conductivity microwave dielectric ceramic material of the present invention has a simple preparation process, high thermal conductivity and Q×f value and an appropriate dielectric constant, and can be used as a multilayer ceramic component material and a circuit substrate material in the field of electronic packaging.

The invention belongs to the technical field of potassium ion batteries, and relates to a composite phase layered oxide positive electrode material and a preparation method and application thereof.The chemical formula of the positive electrode material is KxMnaLibMgcTidNieO2, x is larger than or equal to 0.3 and smaller than or equal to 0.8, a is larger than or equal to 0.2 and smaller than or equal to 0.96, and 1lt is larger than or equal to 0.2 and smaller than or equal to 0.96; b is less than or equal to 0.2, 0lt; c < = 0.2, 0lt; d is less than or equal to 0.2, 0lt; e < = 0.2; the positive electrode material is a potassium ion battery composite phase layered positive electrode material synthesized by a solid-phase reaction method; the preparation method comprises the following two steps: 1, ball-milling a mixture of a K source, a Li source, a Mg source, a Ti source, a Ni source and a Mn source in proportion to obtain a mixture; 2, calcining the mixture prepared in the step 1 to obtain a layered oxide positive electrode material; the oxide positive electrode material can be obtained through calcination by adopting two steps of a solid-phase reaction method, and the positive electrode material can be used for preparing a potassium ion battery; the preparation method is simple, efficient, high in yield and suitable for large-scale industrial production.

The application relates to the technical field of inorganic nonmetal functional ceramic materials, and discloses a polar vortex structure relaxor ferroelectric ceramic material and a preparation method and application thereof, the material is of a chemical formula (1-x)(0.7NaNbO3-0.3Sr 0.7 Bi 0.2 TiO3)-xCaSnO3, wherein 0<=x<=0.2, and a characteristic value is x=0.1. By adopting a step-by-step solid-phase reaction method, NaNbO3, Sr 0.7 Bi 0.2 TiO3 and CaSnO3 ceramic powders are pre-synthesized, then are ball-milled according to a stoichiometric ratio and are sintered into ceramics. The prepared ceramic material has a multi-phase coexistence, core-shell and polar vortex structure, and exhibits high saturation polarization intensity, low hysteresis, large breakdown field strength and excellent service stability, and has potential application in high-power pulse devices. The material is environment-friendly and simple in process, and is expected to provide a new technical path for design and preparation of high-performance and high-stability nonlinear dielectric energy storage materials.

The invention discloses MgNb2O6 dielectric ceramic with excessive Mg and a preparation method of the MgNb2O6 dielectric ceramic, and belongs to the technical field of dielectric ceramics, MgNb2O6 + x mol.% MgO (x is greater than 0 and less than or equal to 3) dielectric ceramic is prepared by adopting a solid-phase reaction method, and excessive Mg ions do not change the phase structure of the ceramic but can inhibit abnormal growth of ceramic crystal grains, so that the crystal grains are more uniform. Besides, along with the increase of excessive Mg ions, the dielectric constant epsilon r and the quality factor Q * f of the MgNb2O6 ceramic are in a trend of firstly increasing and then decreasing, and when x is equal to 2, the ceramic has the optimal dielectric properties that epsilon r is equal to 20.37, Q * f is equal to 85 and 410 GHz, and tauf is equal to-62.21 ppm / DEG C.

The invention discloses a high-quality ternary ceramic piezoelectric material as well as a preparation method and application thereof, the chemical formula of the material is (0.9-x) BiLaO3-xPbTbO3-0. 1PbCeO3, and x is more than or equal to 0.1 and less than or equal to 0.8; the preparation method of the material comprises the following steps: step 1, respectively weighing Bi2O3, PbO, La2O3, TbO2 and CeO2, mixing, carrying out wet ball milling, drying and grinding to obtain a mixture A; step 2, putting the mixture A into a muffle furnace, pre-sintering in an air atmosphere, and sequentially grinding, carrying out wet ball milling and drying to obtain powder B; step 3, adding an adhesive solution into the powder B, grinding and granulating to obtain a granular material; step 4, putting the granular material into a mold, and tabletting to obtain a ceramic blank body; 5, the ceramic blank is transferred to a muffle furnace and calcined in the air atmosphere, and the high-quality ternary ceramic piezoelectric material.The ternary ceramic piezoelectric material is prepared through a solid-phase reaction method, the process is simple, batch production is easy to achieve, and the synthesized ternary ceramic piezoelectric material has the high piezoelectric property, the high dielectric property and the low piezoelectric loss.

The invention discloses a piezoelectric ceramic material with low hysteresis and wide temperature range stability electrostrictive strain in a low electric field and a preparation method and application thereof, and belongs to the technical field of functional ceramic materials. The piezoelectric ceramic material is prepared by combining a traditional solid-phase reaction method with a two-step method. The method mainly comprises the following steps: weighing raw materials, ball-milling, calcining, granulating, forming, degumming and sintering. The chemical composition of the piezoelectric ceramic material is xSm-yPbHfO3-zPb (Sc1 / 2Ta1 / 2) O3-(1-y-z) PbTiO3 (Sm-PH-PST-PT), x is larger than or equal to 0 and smaller than or equal to 0.03, y is larger than or equal to 0.25 and smaller than or equal to 0.5, and z is larger than or equal to 0.05 and smaller than or equal to 0.31. According to the piezoelectric ceramic material, through component optimization and microstructure regulation and control, the unipolar strain fluctuation rate in a wide temperature range (25 DEG C to 200 DEG C) under a low electric field of 2kV / mm is smaller than or equal to 4.4%, excellent temperature stability is shown, the application requirements of a piezoelectric actuator in a wide temperature range and at a high temperature can be met, and the piezoelectric ceramic material has remarkable application value.

The present application relates to a series of compounds calcium halogenated borate and calcium halogenated borate nonlinear optical crystal and preparation method and use, the molecular general formula of the series of compounds is Ca2B3O6X, wherein X=Cl, Br, molecular weight 244.04-288.50, the compound is synthesized using solid phase reaction method;The crystal is orthorhombic, space group Cmc 21, the cell parameter is a=15.360 (6)-15.406 (2) Å, b=22.115 (3)-22.175 (10) Å, c=7.3617 (11)-7.454 (4) Å, Z=16, V=2508.2 (6)-2538.7 (19) Å 3 , the crystal is grown using cosolvent method, the powder frequency doubling effect is about 1.5-2 times of KDP (KH2PO4), has wide light transmission waveband, the crystal preparation method is simple, and the cost is low, the prepared crystal is large in mechanical hardness, easy to cut, polishing processing and preservation, the series of calcium halogenated borate nonlinear optical crystal described in the application has the advantages of stable physical and chemical properties, moderate mechanical hardness, not easy to break, easy to cut, polishing processing and preservation and the like.

The invention relates to an alkali metal composite molybdate compound, an alkali metal composite molybdate nonlinear optical crystal and a preparation method and application of the alkali metal composite molybdate compound and the alkali metal composite molybdate nonlinear optical crystal, the chemical general formulas of the compound and the crystal are KAMo2O7, A is Rb or Cs, the crystal belongs to an orthorhombic system, the space group is Ama2, and the cell parameter # imgabs0 # # imgabs1 # Z is 4. The alkali metal composite molybdate compound is synthesized by adopting a solid-phase reaction method, the nonlinear optical crystal grows by adopting a high-temperature melt method or an aqueous solution method, and the nonlinear optical crystal can be used for manufacturing a second harmonic generator, an upper frequency converter, a lower frequency converter, an optical parametric oscillator and the like.

The invention discloses a preparation method of barium titanate powder for preparing a multilayer ceramic capacitor, which comprises the following steps: respectively preparing a barium source and ammonium bicarbonate into solutions, mixing, stirring at room temperature, standing, precipitating and filtering to obtain high-purity barium carbonate; the preparation method comprises the following steps: uniformly mixing high-purity barium carbonate and titanium dioxide, carrying out ball milling to obtain slurry, drying the slurry, grinding, sieving, calcining, and cooling to obtain barium titanate powder; the preparation method comprises the following steps: adding barium titanate powder and a modified additive into water, carrying out ultrasonic dispersion, drying to obtain mixed powder, carrying out secondary sintering on the mixed powder, and carrying out mixing and ball milling on a product obtained by sintering and bismuth stearate to obtain the modified barium titanate powder. The BaTiO3 powder is successfully and efficiently prepared from different barium sources through a solid-phase reaction method, and the BaTiO3 powder has a larger specific surface area; the metal elements added through modification can enable barium titanate crystal grains to bear higher voltage, so that the breakdown voltage of the MLCC prepared from the barium titanate powder is improved, and the durability of the MLCC is improved.

This invention belongs to the field of lead-free piezoelectric ceramics, and particularly relates to a method for preparing piezoelectric ceramics that directly obtains piezoelectric properties. The method includes the following steps: (1) preparing BDTbT-CCdW via a solid-state reaction method, and grinding the synthesized BDTbT-CCdW into submicron powder using a colloid mill; (2) preparing BaASTB glass powder via a containerless air suspension process; (3) uniformly mixing the BDTbT-CCdW powder and BaASTB glass powder using a high-energy ball mill; (4) preparing BT-based piezoelectric ceramics via rapid calcination and cooling. During the rapid cooling process, the glassy phase BaASTB pins to the grain boundaries, shrinks to generate compressive stress, and induces piezoelectric properties, allowing BT-based ceramics to directly obtain piezoelectric properties without polarization and without depolarization.

The invention provides a Ba-doped rare earth chromate ceramic material with high infrared emissivity and a preparation method of the Ba-doped rare earth chromate ceramic material, and belongs to the technical field of thermal barrier coating ceramic materials. The chemical general formula of the Ba-doped rare earth chromate ceramic material with high infrared emissivity is RE1-xBaxCrO3, x is more than or equal to 0.01 and less than or equal to 0.1, and RE is one of La, Nd and Sm. The grain size of the Ba-doped rare earth chromate ceramic material with high infrared emissivity is 0.5-10 [mu] m, the porosity is 0-10%, and the average emissivity of the Ba-doped rare earth chromate ceramic material at the infrared band of 200-2000 nm is not lower than 90%. The preparation method is a solid-phase reaction method. The Ba-doped rare earth chromate ceramic material with high infrared emissivity prepared by the invention has flexible and adjustable infrared emissivity, and the infrared emissivity can be adjusted by changing the doping amount of the Ba element. A solid-phase reaction method adopted for preparing the Ba-doped rare earth chromate ceramic material with high infrared emissivity is low in raw material cost, simple in process and low in equipment requirement.

The invention provides a lithium manganese iron phosphate positive electrode material and a preparation method and application thereof, and in the preparation method of the lithium manganese iron phosphate positive electrode material, a multistage chelation system is constructed through a chelation coordination strategy, and the dispersibility and stability of the chelation system in the preparation process of the lithium manganese iron phosphate positive electrode material are improved in cooperation with a gelation technology. According to the preparation method, the growth environment of the lithium manganese iron phosphate positive electrode material crystal can be effectively optimized, the element segregation phenomenon in the process of preparing the lithium manganese iron phosphate positive electrode material through a traditional solid-phase reaction method, a hydrothermal method and other methods is improved, and the conductivity and the lithium ion diffusion rate of the prepared lithium manganese iron phosphate positive electrode material can be improved; and the rate capability and the cycling stability of the material can also be enhanced. When the lithium manganese iron phosphate positive electrode material prepared by the preparation method is applied to the lithium ion battery, the battery capacity and the cycling stability of the lithium ion battery can be further improved.

The invention discloses a method for synthesizing powder nano oxide by transient pulse heating, which comprises the following steps of: (1) uniformly mixing one heat-sensitive metal salt or at least two heat-sensitive metal salts to obtain a reaction precursor; (2) loading the reaction precursor obtained in the step (1) into a heating matrix with thermal conductivity or electrical conductivity; (3) performing pulse heating under the atmosphere condition; and (4) naturally cooling to obtain the nano oxide powder. Compared with a traditional solid-phase reaction method, a hydrothermal method and the like, the method provided by the invention has the advantages of short reaction time, low energy consumption, simple equipment, good product dispersity and the like, is suitable for large-scale preparation of high-performance nano materials in the fields of catalysis, energy, electronics, environmental protection and the like, and has a better application prospect.

The application provides a high-entropy oxygen storage material and a preparation method thereof, and belongs to the technical field of oxygen storage materials. (4‑n) X n O 7+δ Wherein, δ is the oxygen adsorption molar quantity, 0 < δ ≤ 1.5; X is at least five kinds of Cu, Fe, Zn, Ga, Al and Mn; and n is the doping amount of X metal elements, 0 < n ≤ 1. The preparation method of the high-entropy oxygen storage material comprises a solid-phase reaction method, a sol-gel method or an electrostatic spinning method. The oxygen storage material is modified by high-entropy based on YBaCo4O 7+δ Oxide, through the selection and content control of the doped metal elements, the synergistic effect among multiple sites is exerted, the thermal stability of the material is significantly improved, and the working temperature window is widened.

This invention discloses a solid-state reaction preparation method for zinc manganate ceramics and its doping modification method, belonging to the technical field of zinc manganate ceramic preparation and doping modification. This invention solves the problem of difficulties in synthesizing ZnMn2O4 ceramics using existing solid-state reaction methods. This invention successfully prepares ZnMn2O4 ceramics using a two-step sintering method via solid-state reaction. Addressing the issue of high loss in ZnMn2O4 ceramics, which prevents them from being used as voltage regulators for extended periods, this invention modifies the zinc manganate ceramics by doping. The local stress and electric fields formed by the dopant ions induce controllable changes in the varistor and dielectric properties of the zinc manganate ceramics, achieving effective control of the nonlinear conductivity coefficient. Furthermore, the threshold electric field is adjustable, broadening the application range of zinc manganate ceramics.