234 results about "Strontium titanium oxide" patented technology

High quality epitaxial layers of monocrystalline III-V arsenide nitride materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. One way to achieve the formation of a compliant substrate includes first growing an accommodating buffer layer on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline III-V arsenide nitride material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, an accommodating buffer layer comprising a barium strontium titanium oxide and a monocrystalline III-V arsenide nitride layer, such as GaAsN, having a nitrogen concentration ranging from 1-5% function to further reduce any lattice mismatch between layers.

The invention discloses a hollow fiber membrane reactor for gaseous oxidation reaction, a preparation method and application thereof. The membrane reactor is made of a compact hollow fiber oxygen permeation membrane, wherein the wall thickness of a pipe is between 0.1 and 0.3mm, and the outer pipe diameter is between 1 and 3mm; the oxygen permeation membrane is made of a dual-phase composite ceramic oxygen permeation membrane material which is prepared by mixing an electron conductive phase material and an ion conductive phase material in a volume ratio of 0.43-1.5:1; the electron conductive phase material is provskite-type chromic lanthanum composite oxide (Ln1-xAx)1-zCr1-yByO3 and/or strontium titanate-based composite oxide (LnxSr1-x)1-zTi1-yByO3; and the ion conductive phase material is stabilized fluorite type zirconium dioxide Zr1-x1Rx1O2-delta, or doped cerium dioxide R'z1Ce1-z1O2-delta. The method for preparing the membrane reactor comprises the following steps: mixing the electron conductive phase material and the ion conductive phase material in the volume ratio of 0.43-1.5:1 to prepare a hollow fiber membrane blank by adopting a wet phase inversion method; and sintering the blank at the temperature of between 1,300 and 1,600 DEG C for 10 to 18 hours. The membrane reactor has high oxygen permeation performance, excellent high temperature reduction resistance and long-term stability and low production cost.

The invention discloses a two-phase composite ceramic material of being used to microwave modulator, which comprises 80.0-20.0wt% Ba(1-x)SrxTiO3(x=0.3-0.6) and 20.0-80.0wt% Mg2TiO4. The invention is characterizes by the following: adopting traditional electronic ceramic preparing craft; selecting microwave dielectric material normal magnesium titanate with good dielectric property; proceeding two-phase gradient composition with strontium titanate barium ferroelectric materials different Ba/Sr ingredient; getting the product.

The invention particularly relates to a high-performance semiconductor ultraviolet photoelectric detector and a preparation method thereof, wherein for the high-performance semiconductor ultraviolet photoelectric detector, an ultra-thin silicon chip is used as a substrate, a nano TiO2/SrTiO3 heterojunction active layer is used as a base material, and Au is used as a metal interdigitated electrode. The preparation method comprises the following steps of: preparing a TiO2 and SrTiO3 sol by adopting a sol-gel technology, and growing a compact nano SrTiO3 film and a compact TiO2 film in order on the ultra-thin silicon substrate; and preparing the Au interdigitated electrode with a certain shape on the surface of the films through adoption of a magnetron sputtering technology and a standard photoetching and stripping technology. The TiO2/SrTiO3 heterojunction metal-semiconductor-metal ultraviolet detector prepared with the preparation method disclosed by the invention has the characteristics of simple preparation method, low cost and potentiality in large-scale production, and has a good detection performance for detecting ultraviolet rays of which the wavelength is 250-350 nm.

A preparation method for a strontium titanate lanthanum based powder material belongs to the field of fuel cells. The method adopts a citric acid-nitrate spontaneous combustion method, using citric acid as a complexing agent and a reducing agent, using nitric acid as an oxidizing agent, introducing a sintering acid ammonium nitrate in-situ, dissolving with metal nitrate in deionized water, adding a tetrabutyl titanate citric acid solution to form an even transparent solution, heating in water bath, removing surplus water, forming even sol, and heating the sol in a muffle furnace till spontaneous combustion happens to form fluffy precursor powder. Then Grinding and calcining in an electric furnace to obtain single strontium lanthanum based anode powder. The preparation method has the advantages of being simple in synthesis process, low in cost, fine and even in powder particles and low in material phase forming temperature. The method is also applicable to synthesis preparation of strontium titanate based nanometer powder and can be used for laboratory synthesis and industrial production of a solid oxide fuel cell anode powder material.

The invention discloses a preparation method of a high-performance doping strontium titanate perovskite oxide thermoelectric film. The method is characterized in that epitaxial coherent growth of a doping strontium titanate film material on the surface of an oxide monocrystal substrate which has the same lattice body structure and an unmatched parameter compared with the film material is realized by controlling a plasma property and a substrate condition; and an interfacial stress field is generated. A crystal structure property, an electronic structure property and a polarization characteristic of the film material, and an interfacial property between the film material and the substrate are adjusted by the stress field and the lattice distortion degree of the film material, so that thermoelectric transmission properties of the material such as conductivity and a seebeck coefficient are greatly improved. A room-temperature thermoelectric power factor of the prepared doping strontium titanate film material is 50-10000mnW/(cm*K<2>). The high-performance doping strontium titanate film material prepared by the method can be further applied to design and preparation of a thermoelectric device, so that the thermal and electric energy conversion efficiency of the prepared thermoelectric device during realization of functions such as temperature difference power generation, refrigeration and temperature sensing can be greatly improved.

The invention provides a method for preparing strontium titanate powder. The method comprises the following steps in sequence: adopting a titanium tetrachloride solution and a strontium chloride solution as the raw materials, and a sodium carbonate solution and a sodium hydroxide solution as precipitators; carrying out liquid-phase chemical coprecipitation reaction on the raw materials and the precipitators, so as to obtain a precursor precipitate of the strontium titanate; separating the precipitate from the reaction solution system; washing; drying; and dynamically roasting at a high temperature in a rotating way, so as to obtain the strontium titanate powder. The method is environment-friendly, simple in technological process, and convenient for industrial production; and the prepared strontium titanate powder is stable in quality, and high in purity and uniformity.

Novel anode materials including various compositions of vanadium-doped strontium titanate (SVT), and various compositions of vanadium- and sodium-doped strontium niobate (SNNV) for low- or intermediate-temperature solid oxide fuel cell (SOFCs). These materials offer high conductivity achievable at intermediate and low temperatures and can be used as the structural support of the SOFC anode and/or as the conductive phase of an anode. A method of making a low- or intermediate-temperature SOFC having an anode layer including SVT or SNNV is also provided.

The invention relates to barium strontium titanate-based superfine powder and a preparation method thereof. The powder is Ba1-xSrxTiO3, wherein x=0.2-0.8; or the powder is Ca2+ doped Ba1-z-ySrxCayTiO3, wherein z=0.2-0.7 and y=0-0.2. The method comprises the following steps of: preparing salt solution, buffer solution of ammonium nitrate, oxalic acid solution, ethanol solution of titanium butoxide and acid solution of titanyl oxalate monohydrate; performing coprecipitation reaction; and ageing, drying and calcining to obtain barium strontium calcium titanate powder. The barium strontium titanate-based superfine powder with the advantages of a little agglomeration, high dispersability, and high chemical activity is prepared by the chemical copercipitation method, accords with a stoichiometric ratio, has the advantages of small grain size, high uniformity, a little agglomeration, large specific surface area, and high chemical activity, and contributes to the compactness and sintering performance of the prepared ceramic capacitor materials.

The invention discloses a lithium-sulfur battery composite positive electrode material. Graphene oxide is used as a matrix of the battery positive electrode material, a graphene/ferroelectric composite material is obtained after the graphene oxide and a ferroelectric material are compounded, and then the graphene/ferroelectric composite material is mixed with nano sulfur according to a mass ratio of 3:7 to prepare the lithium-sulfur battery composite positive electrode material; and the ferroelectric material is one of barium titanate, lead titanate, potassium niobate, strontium titanate, lithium niobate or lead zirconate titanate. According to the lithium-sulfur battery composite positive electrode material disclosed by the invention, excellent electrical conductivity and structural stability of the graphene oxide are utilized, and the graphene oxide is used as an excellent conductive network and the positive electrode matrix, so that electrical conductivity of the positive electrode material is improved; and by utilizing strong adsorption of ferroelectricity of the ferroelectric material on polar polysulfide, dissolution and shuttling of the polysulfide in electrolyte are inhibited, so that loss of active substances is reduced, coulombic efficiency of a lithium-sulfur battery is improved and a cycle life of the lithium-sulfur battery is prolonged.

The invention discloses a strontium titanate dielectric layer based meta-material wave absorbing device and a manufacturing method thereof. The wave absorbing device comprises a bottom structure, a middle dielectric layer and a top resonance structure, the bottom structure comprises at least a metal film layer, and the middle dielectric layer is fixed on the bottom structure. The top resonance structure is fixed on the middle dielectric layer, and comprises metal resonance structures arranged in an array. The metal resonance structures are all fixed in the end surface, far from the bottom structure, of the middle dielectric layer. The metal film and metal resonance structures are made of copper, and the middle dielectric layer is made of a SrTiO3 material. The SrTiO3 material serves as themiddle dielectric layer of the meta-material wave absorbing device, the outside ambient temperature can be changed to adjust the wave absorbing frequency and intensity actively, further the application field of the meta-material wave absorbing device is widened, incident electromagnetic waves in the terahertz frequency is controlled effectively, and development and application of terahertz science and technology are facilitated.

The invention discloses a preparation method of an energy storage tungsten trioxide/strontium titanate/titanium dioxide nanometer composite film photoanode, and relates to a photoanode. A titanium foil is used as a basal body for ultrasonic operation in acetone, anhydrous ethanol and de-ionized water; a titanium basal body sample is used as an anode; a platinum piece is used as a cathode; after the anode is oxidized, a prepared sample is cleaned and dried to obtain a TiO2 nanotube array film; the TiO2 nanotube array film is put in a polytetrafluoroethylene reaction kettle; mixed solution containing Sr(COOH)2 and KOH is added for hydrothermal reaction; the sample is taken out to dip in HCl solution for cleaning, drying and calcining; and a SrTiO3/TiO2 composite film is obtained. The SrTiO3/TiO2 composite film is used as a working electrode; the platinum piece and a saturated calomel electrode are used as an auxiliary electrode and a reference electrode; constant potential is applied to an electrolytic cell for electric deposition to prepare WO3 on the surface of the SrTiO3/TiO2 composite film; and the sample is flushed by de-ionized water, and is calcined after drying to obtain the photoanode.

The invention discloses preparation of a BiVO4/SrTiO3 composite photocatalyst, and is mainly applied to the technology of photocatalytic hydrogen production from water decomposition. A preparation method of the BiVO4/SrTiO3 composite photocatalyst disclosed by the invention comprises the following steps: stirring BiVO4 and dispersing the BiVO4 in distilled water in an ultrasonic manner, then adding SrTiO3, stirring and processing in an ultrasonic manner; evaporating to dry the mixture in a water bath at a constant temperature of 40-60 DEG C; finally transferring into a muffle furnace, and calcining for 1-2 hours at a temperature of 450-500 DEG C to obtain the BiVO4/SrTiO3 composite photocatalyst. According to the preparation method disclosed by the invention, a hydrogen producing material SrTiO3 serves as a main body, and a heterojunction composite material is formed by compositing the SrTiO3 with the SrTiO3, so as to increase the migration rate of photoinduced electrons on a semiconductor BiVO4 interface, meanwhile the absorption range of the SrTiO3 in solar energy spectrum is widened, and therefore the performance of the SrTiO3 on photocatalytic hydrogen production from water decomposition is improved. Experimental results show that hydrogen production of the photocatalyst can reach 611.6mu mol/g in the process of hydrogen production from water decomposition.

The invention relates to a heat-resisting sintered neodymium iron boron permanent magnet material and a preparation method thereof. Neodymium iron boron powder is composed of 18.6-23.1% of Nd, 0.73-0.81% of B, 0.44-0.53% of Cu, 0.95-1.03% of Co, 0.41-0.46% of Ga, 0.67-0.73% of Nb, 0.67-0.73% of Nb, 2.6-3.1% of Dy, 0.23-0.29% of Al and the balance Fe. The heat-resisting sintered neodymium iron boron permanent magnet material is prepared by adding nano-iron powder, nano strontium titanate and nano vanadium nitride into the neodymium iron boron powder with uniform mixing prior to sintering. The heat-resisting sintered neodymium iron boron permanent magnet material has the advantages that an optimal ingredient formula is adopted, appropriate nano elements are added, and through a special mixing manufacturing technique, a neodymium iron boron magnet which is high in performance and and heat stability can be produced; the neodymium iron boron magnet is small in size of grain boundary angle pair, more regular in shape and homogenized, refined and regular in crystalline grain, and the magnet has higher corrosion resistance and heat resistance.

The invention discloses a photo-thermal induced voltage thin-film material having response time of less than 10 ns, and the application of the material. Lal-xSrxCoO3 serves as a quick-response induced voltage material, wherein x is equal to 0.1 to 0.6. A thin film is grown on an inclined strontium titanate (SrTiO3) single-crystal substrate by using a pulse laser deposit technology and has photo-thermal radiation induced voltage effects. Pulse laser light of which the pulse width is 28 ns and the wavelength is 248 nm is irradiated to the thin film, a quick-response large voltage signal of which the response time is 7 ns and the full width at half maximum is 17ns is obtained in the inclination direction of the thin film, and the voltage signal is acquired by a high-frequency oscilloscope. The photo-thermal induced voltage thin-film material is characterized in that: the response time is short; the material can operate at a wide optical spectrum of 0.19 to 11 mu m; the operation flow is easy, and energy sources are saved; the material can be used for manufacturing quick-response photo-thermal induced voltage detector devices; the response speed of a photo-thermal measuring instrument is increased; and the material is applicable to sensitive detection and tracking of pulse photo-thermal signals and military targets in the technical field of industry and the field of life.

A high-temperature structural material which not only has a coefficient of thermal expansion close to the coefficient of thermal expansion of an electrolyte material, but also undergoes no decrease in mechanical strength even in a reducing atmosphere, and can be sintered at relatively low temperatures just by adding a predetermined sintering aid, a structural body for a solid electrolyte fuel cell, which is formed with the use of the high-temperature structural material, and a solid electrolyte fuel cell including the structural body. The high-temperature structural material contains strontium titanate and aluminum, wherein the aluminum is in an amount of 10 parts by mol or more and 60 parts by mol or less with respect to 100 parts by mol of the strontium titanate.

Provided is an electrophotographic developing agent including: toner particles including a binder resin, a colorant, and a charge control agent; and an external additive added to the surface of the toner particles, wherein the external additive includes at least one inorganic particulate component and at least two types of strontium titanate particulate component having different mean primary particle diameters. Typically, the inorganic particulate component is not strontium titanate. Also, an electrophotographic image forming apparatus using the electrophotographic developing agent is provided. The strontium titanate particulate component having different mean primary particle diameters are used as an external additive to maintain uniform charging characteristics and to prevent fog in a non-image area, thereby obtaining good image quality. In addition, the external additives prevent deposition of the developing agent on a developing agent regulating blade due to stress when the developing agent is used for a long time.

The invention belongs to the field of capacitor dielectric material preparation and relates to a dielectric ceramic material with high-temperature stability and a preparation method thereof. The preparation method comprises the following steps of: pre-synthesizing base materials including barium titanate (BaTiO3), strontium titanate (SrTiO3), lead titanate (PbTiO3), calcium zirconate (CaZrO3) andBi2O3.nTiO2 by using barium carbonate (BaCO3), strontium carbonate (SrCO3), calcium carbonate (CaCO3), lead oxide (PbO), bismuth trioxide (Bi2O3), zirconium oxide (ZrO2) and titanium oxide (TiO2) as raw materials and by a solid-phase synthesis process, wherein n is 1 to 5; according to a proportioning requirement, mixing the base materials and auxiliary additives including magnesium oxide (MgO) and manganese carbonate (MnCO3) and performing resynthesis by the solid-phase synthesis process; and then preparing the dielectric ceramic material with high-temperature stability by the preparation process of the conventional dielectric ceramic material. According to detection, a ceramic capacitor manufactured by the dielectric ceramic material has the electrical characteristics that: the temperature change rate, namely absolute value of delta epsilon/epsilon25, is less than or equal to 5 percent (between 25 DEG C below zero and 85 DEG C); the dielectric constant epsilon25 is more than or equal to 1,000; the tangent tg delta of a loss angle is less than or equal to 1 percent; and the breakdown voltage VBDC is more than or equal to 10 KV/mm.

An embodiment of the invention provides a germanium-based NMOS device and a method for fabricating the same, which relates to fabrication process technology of an ultra-large-scale-integrated (ULSI) circuit. The germanium-based NMOS device has two dielectric layer interposed between a metal source/drain and a substrate. The bottom dielectric layer includes a dielectric material having a high pinning coefficient S such as hafnium oxide, silicon nitride, hafnium silicon oxide or the like, and the top dielectric layer includes a dielectric material having a low conduction band offset ΔE_C such as titanium oxide, gallium oxide, strontium titanium oxide or the like. According to the method, Fermi level pinning effect can be alleviated, electron barrier height can be lowered, and thus performance of the germanium-based Schottky NMOS device can be improved. Compared with a conventional single dielectric layer such as aluminum oxide (Al₂O₃), Schottky barrier height can be lowered while low source/drain resistances can be maintained, and thus performance of the device can be significantly improved.