45 results about "Solid state reaction method" patented technology

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 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 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 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.

This invention provides a Si-doped lithium gallium oxide thin-film solar-blind ultraviolet detector, its fabrication method, and its application. The fabrication method includes the following steps: mixing SiO2, Li2CO3, and Ga2O3 polycrystalline powders, and using a solid-state reaction method to obtain Li... y (Ga 1‑x Si x 5O8 polycrystalline target material; Li was prepared on the substrate using pulsed laser deposition. y (Ga 1‑x Si x )5O8 thin film; subsequently in Li y (Ga 1‑x Si x Electrode deposition on 5O8 thin film. Compared with undoped Si Li 0.9 Compared with Ga5O8 thin-film detectors, the solar-blind ultraviolet detector provided by this invention has improved the on / off ratio, responsivity, and detectivity by up to 1177 times, 1130 times, and 1153 times, respectively, and shortened the response time by up to 0.5 s. It has stable working performance and can be applied to fields involving solar-blind ultraviolet signal detection, such as forest fire monitoring and missile exhaust tracking.

The application discloses a conductive ceramic additive / solid electrolyte composite material and a preparation method thereof, and belongs to the technical field of solid electrolyte materials. The application solves the problem of low room temperature ionic conductivity of existing solid electrolyte materials. The material is of a chemical formula xLaNbO4-yNZSP / zLATP / alphaLLT / beta8YSZ or beta3YSZ / gammaSrTiO3, 0.5mol%<=x<=3mol%, and y, z, alpha, beta and gamma have only one of them being not 0; NZSP is Na 3.4 Zr2Si 2.4 P 0.6 O 12 , LATP is Li 1.5 Al 0.5 Ti 1.5 P3O 12 , LLT is Li 0.34 La 0.56 TiO3, and YSZ is 3YSZ or 8YSZ. The method is a solution assisted solid phase reaction method or a sol-gel esterification method. The process is simple, the cost is low, and the obtained solid electrolyte material has high ionic conductivity at room temperature.

The invention discloses pure-phase bismuth ferrite ceramic as well as a preparation method and application thereof, and belongs to the field of lead-free ferroelectric ceramic. Comprising the following steps: putting pure-phase bismuth ferrite precursor powder prepared by a hydrothermal method into a graphite mold, controlling the heating rate, heating to a sintering temperature, applying pressure, keeping the temperature, sintering, and finally preparing the pure-phase bismuth ferrite ceramic. According to the pure-phase bismuth ferrite ceramic prepared through SPS sintering, volatilization of Bi < 3 + > and generation of impure phases are effectively inhibited. The bismuth ferrite ceramic shows good magnetic performance, the magnetic performance is enhanced, good dielectric stability is shown, and the bismuth ferrite ceramic has certain ferroelectricity and good energy storage performance. Aiming at the problems that pure-phase bismuth ferrite ceramic is difficult to prepare by a traditional solid-phase reaction method, a mixed phase is generated due to Bi < 3 + > volatilization and oxygen vacancy defects caused by high-temperature sintering, multiferroic performance is unstable and the like, the preparation process of the bismuth ferrite ceramic is optimized by adopting a mode of combining a hydrothermal method and spark plasma sintering (SPS).

The present application relates to a kind of purple light high response green fluorescent material, the chemical expression of the fluorescent material is Lu2SiO5:xEu 2+ Wherein 0.01≤x≤0.05.Compared with prior art, the present application is a kind of wide excitation green fluorescent powder, it is a kind of new fluorescent material, has the advantage of physical and chemical properties stable, meanwhile, the fluorescent powder can be prepared by conventional solid phase reaction method.The present application fluorescent powder can be well matched with existing purple light chip, under the excitation of 400nm, keep about 75% of the best emission intensity, luminous performance is excellent, has the great development potential of being applied to the health lighting field such as purple light excitation white light LED, purple light excitation sunlight LED, purple light excitation full spectrum LED.

The application relates to a high-temperature negative temperature coefficient thermosensitive ceramic material and a preparation method thereof. 1‑ x Nb x O3 is prepared by a solid phase reaction method. The following raw materials are weighed according to percentage by weight: lanthanum sesquioxide 73.315-76.112%, aluminum sesquioxide 20.701-23.888%, and niobium pentoxide 1.540-5.985%; the preparation method comprises the following steps: S1. weighing; S2. mixing; S3. grinding; S4. pre-sintering; S5. secondary grinding; S6. tabletting; S7. cold isostatic pressing; S8. sintering; S9. platinum slurry coating; and S10. annealing. The high-temperature negative temperature coefficient thermosensitive ceramic material has a wide temperature range (600-1400 DEG C) and excellent aging stability; after aging for 400-600 hours at a high temperature of 1000 DEG C, the resistance drift rate of the LaAl 1‑x Nb x O3 sample is 0.906-3.352%, and the service life is long; in addition, the powder particles prepared by the application have high dispersity and are not prone to agglomeration, and the material strength is high.

The invention relates to the technical field of inorganic nonmetal functional ceramic materials, and discloses a dislocation-induced polar vortex structure relaxor ferroelectric ceramic material as well as a preparation method and application thereof, the chemical formula of the material is (1-x) Ba < 0.5 > Bi < 0.5 > Ti < 0.5 > Fe < 0.5 > O < 3-x > Ca < 0.7 > La < 0.2 > ZrO < 3 >, x is greater than or equal to 0 and less than or equal to 0.2, and the characteristic value is x = 0.1. The preparation method comprises the following steps: synthesizing Ba0. 5Bi0. 5Ti0. 5Fe0. 5O3 and Ca0. 7La0. 2ZrO3 ceramic powder in advance by adopting a step-by-step solid-phase reaction method, carrying out ball-milling mixing according to a stoichiometric ratio, and sintering to obtain the ceramic. The prepared ceramic material has two-phase coexistence, high-concentration double-charge oxygen vacancies, dislocation lines penetrating through a core-shell layer and a polar vortex structure, shows high saturation polarization intensity, low hysteresis, large breakdown field strength and excellent service stability, and has potential application in high-power pulse devices.

The invention belongs to the technical field of magnetic refrigeration materials, and particularly discloses a potassium europium phosphate extremely-low-temperature magnetic refrigeration material and a preparation method and application thereof. The material KEuPO4 belongs to an orthorhombic system, and the space group is Pnma; the polycrystalline block of the material can be prepared by adopting a step-by-step solid-phase reaction method in a hydrogen-argon mixed gas atmosphere. The magnetic phase change temperature of the material ranges from 1.0 K to 1.2 K along with the reversible giant magnetocaloric effect, under the magnetic field changes of 0-2 T and 0-5 T, the maximum isothermal magnetic entropy change values of the material range from 32.8 J / kg.K to 33.4 J / kg.K and 49.7 J / kg.K to 52.1 J / kg.K respectively, and the maximum isothermal magnetic entropy change values of the material are both superior to those of a commercial extremely-low-temperature magnetic refrigeration material Gd3Ga5O12. The europium-based phosphate KEuPO4 material provided by the invention has the advantages of simple preparation process, good material stability, remarkable magnetocaloric effect and the like, and has a relatively good application prospect in the field of extremely low-temperature magnetic refrigeration.

The invention belongs to the technical field of inorganic non-metallic materials, and particularly relates to an A-site silicon-containing MAX-phase layered material and a preparation method and application thereof, the molecular formula of the MAX-phase layered material is Mn + 1AXn, M is one or more of IIIB, IVB, VB or VIB group elements; a is a silicon element or an alloy formed by silicon and other main group elements or subgroup elements in any proportion; x is one or more of carbon, nitrogen and boron; n is 1, 2, 3 or 4; the preparation method comprises a gas phase reaction method or a solid phase reaction method, for example, taking an MAX phase precursor and a silicon-containing substance as raw materials, reacting at a specific temperature and atmosphere, and washing and drying to obtain a target product. The method is easy and convenient to operate and wide in applicability, and controllable preparation of the A-site silicon-containing MAX phase with the M site being a non-titanium element is achieved for the first time. According to the invention, the material system of the Si-MAX phase is obviously expanded, and the problems that the original Si-MAX phase is limited in variety and the M-site element type is limited are solved.

The invention belongs to the technical field of microwave dielectric ceramic materials, and particularly relates to a cordierite-based ceramic material with ultrahigh Q * f and a preparation method thereof. According to the invention, Si element in Mg2Al4Si5O18 is replaced by (Mn0. 5Ti0. 5) 4 composite particles, so that the lattice structure of Mg2Al4Si5O18 is regulated and controlled, the symmetry of a [O6] six-membered ring and a [Si4Al2] hexagonal ring and the deformation of a [MgO6] octahedron are improved, and finally, the optimization of dielectric properties is realized. Finally, the Mg2Al4Si5-x (Mn0. 5Ti0. 5) xO18 (x is greater than or equal to 0 and less than or equal to 0.16) ceramic material is prepared by a traditional solid-phase reaction method and is successfully sintered at 1350-1390 DEG C. The dielectric properties of the Mg2Al4Si4.96 (Mn0. 5Ti0. 5) 0.04 O18 ceramic are as follows: epsilon r is equal to 4.907, Q * f is equal to 159681 GHz, and andtauf is equal to-21.075 ppm / DEG C. The invention also discloses a preparation method of the Mg2Al4Si5-x (Mn0. 5Ti0. 5) xO18 ceramic material. And a foundation is provided for application of the cordierite-based ceramic material with ultrahigh Q * f.

The present application relates to a kind of low dielectric loss and low temperature coefficient microwave dielectric ceramic and its preparation method, the preparation method includes the following steps: after mixing zinc lanthanum titanate, strontium source and auxiliary raw material, sequentially forming and sintering, the low dielectric loss and low temperature coefficient microwave dielectric ceramic is prepared;The auxiliary raw material includes any one or combination of at least two of calcium carbonate, manganese dioxide or barium carbonate.The present application selects zinc lanthanum titanate and strontium titanate with good microwave dielectric properties as basic raw material to ensure the basic performance of ceramic;Introduce appropriate amount of calcium carbonate, manganese dioxide and barium carbonate, effectively reduce the dielectric loss of ceramic, and improve its temperature characteristics;The present application reduces production cost and technical difficulty by solid phase reaction method, while ensuring the uniformity and stability of ceramic, effectively reduces the dielectric loss of microwave dielectric ceramic, and improves its temperature characteristics, further improves the performance of ceramic.

This invention relates to the field of dielectric energy storage ceramic materials, specifically to a CaTiO3-based relaxor ferroelectric ceramic material and its preparation method. The general chemical formula of the CaTiO3-based composite relaxor ferroelectric ceramic material is: (1-x)Ca 0.5 Bi 0.25 Na 0.25 TiO3-xBaZrO3, where 0 < x ≤ 0.30, is produced by solid-state reaction method, in which Bi2O3, Na2CO3, CaCO3, TiO2, BaCO3, and ZrO2 are stoichiometrically proportioned, followed by wet ball milling, pre-calcination, granulation, tableting, debinding, and sintering. This invention, by constructing a relaxor ferroelectric heterojunction, synergistically optimizes the breakdown field strength, polarization intensity, and dielectric loss, solving the problems of polarization saturation and low energy storage efficiency in traditional ferroelectrics.

This invention relates to the compounds strontium lanthanum chloroborate and barium lanthanum chloroborate, as well as nonlinear optical crystals of strontium lanthanum chloroborate and barium lanthanum chloroborate, their preparation methods, and their uses. The general chemical formula for both the compounds and crystals is A3La4B3O. 13 Cl, where A = Sr, Ba, space group P63, belongs to the hexagonal crystal system, and cell parameter Z = 2. The compounds lanthanum strontium chloroborate and lanthanum barium chloroborate are synthesized by a solid-state reaction method. The nonlinear optical crystals of lanthanum strontium chloroborate and lanthanum barium chloroborate are grown using a high-temperature melt method. This material can be used to manufacture second harmonic generators, up-down frequency converters, optical parametric oscillators, etc.

The application discloses a europium-based molybdate material, a preparation method thereof and application of the europium-based molybdate material in a very low temperature magnetic refrigeration material, and relates to the field of magnetic refrigeration materials. The chemical structural formula of the europium-based molybdate material is EuMoO4, the europium-based molybdate material has a secondary magnetic phase change below 1K temperature, and can be applied to preparation of a very low temperature magnetic refrigeration material. The europium-based molybdate material has a secondary magnetic phase change under the condition of 1K temperature, and the volume magnetic entropy change of the europium-based molybdate material under a low magnetic field is obviously higher than the maximum volume magnetic entropy change of an existing magnetic refrigeration material under the same magnetic field change, so that the europium-based molybdate material is a very low temperature magnetic refrigeration material with excellent performance. The europium-based molybdate material is synthesized by using a solid phase reaction method, the preparation process is simple, energy consumption is low, and the europium-based molybdate material is suitable for large-scale industrial production.

The invention relates to a wide-frequency-band large-range adjustable equal-magnetic-dielectric hexagonal ferrite material and a preparation method thereof, and belongs to the technical field of advanced ferrite materials and preparation thereof. The chemical formula of the equimagnetic dielectric hexagonal ferrite material is Ba3xAxCo2 + xBxFe242xO41, A is one or more of Sr, Ca, Pb and other elements, B is one or more of Ti, Mo, Zr and other elements, and x is equal to 0.1-1. The magnetic conductivity and the dielectric constant of the material are cooperatively regulated and controlled through a multi-ion combined substitution technology, so that the material realizes large-range magnetic conductivity and dielectric constant matching in a wide frequency band, and the magnetic dielectric loss is relatively low. The method is based on a solid-phase reaction method, the process is mature and controllable, the production cost is low, and the method is suitable for large-scale industrial production.