172 results about "Tantalite" patented technology

The invention relates to a niobate or tantalite fluorescent material used for a white light LED and a preparation method thereof. The material comprises the following components: non-doped niobate or tantalite, transition metal doped niobate or tantalite, T1 like ion doped niobate or tantalite with an s2 configuration, rare-earth element doped niobate or tantalite and T1 like ion and rear earth codoped niobate or tantalite. The materials in the invention can be used for the white light LED and related display and lighting devices. The invention has cheap and easy available materials, simple preparation process, stable material chemical property and excellent luminescence performance, and the prepared niobate or tantalite flourescent material is an ideal fluorescent powder candidate material for the white light LED.

A tantalum powder and/or a niobium powder with high specific surface area are prepared through reaction between the oxides one of tantalum and/or niobium, alkali metal and halide of at least of Mg, Ca, Sr, Ba and Ce. Its advantages are simple preparing process, and high specific surface area, purity and flowability, and thus it is especially suitable for making the anode of capacitor.

The invention discloses a composite single crystal thin film and a method for manufacturing the composite single crystal thin film. The composite single crystal thin film comprises a substrate, an optical isolation layer, a lithium niobate single crystal thin film or a lithium tantalate single crystal thin film and a silicon thin film, wherein the optical isolation layer is located on a substrate; the lithium niobate single crystal thin film or the lithium tantalate single crystal thin film is located on the optical isolation layer; and the silicon thin film is located on the lithium niobate single crystal thin film or the lithium tantalate single crystal thin film. The composite single crystal thin film disclosed by the invention has good nonlinear optical effect, acousto-optical effect, electro-optic effect and the like of a lithium niobate or lithium tantalite material, and simultaneously has the characteristic of a mature processing technology of a silicon material, so that the composite single crystal thin film disclosed by the invention can achieve relatively good compatibility with an existing IC production technology and has a broad industrial prospect. In addition, stable and effective industrial production can be achieved according to the method for manufacturing the composite single crystal thin film disclosed by the invention.

The invention discloses a method for preparing lanthanide rare-earth tantalite ceramic through a solid phase method.The molecular formula of the compound is RETaO4 (RE=Dy, Eu, Lu, Yb, Nd, Gd and Er).The adopted raw materials are Ta2O5, Dy2O3, Eu2O3, Lu2O3, Yb2O3, Nd2O3, Gd2O3 and Er2O3.The raw materials are weighed proportionally, the weighed raw materials are mixed in absolute ethyl alcohol and then placed into a planetary ball mill for ball milling so as to be mixed to be uniform, the mixed powder is dried, screened and placed into a mold to be compacted, and then presintering is performed; cooling is performed, a presintered sample is taken out to be subjected to grinding, ball milling, drying and screening, the screened powder is placed into the mold to be compacted, and then secondary sintering is performed.The technology is high in purity, low in impurity content, low in product preparation cost and suitable for batch production, and the target product is expected to be adopted as a novel high-temperature resistant, antioxidant and anti-wearing ceramic material.

The invention belongs to the technical field of tools for lithium chips and particularly relates to a production process of 6-inch lithium niobate or lithium tantalite chips. The production process includes the steps of A, cutting to obtain chips 0.6-1mm in thickness; B, charging the chips into a reduction furnace for reduction; C, after grinding, cleaning by ultrasonic; D, pasting the chips; E, grinding; F, polishing; G, cleaning, and boxing. Internal stress of the chips is removed by double corroding, electrostatic charge is removed from the chips by blackening, ultra-smooth planes are obtained by mechanical chemical polishing, TTV is smaller than 5 um, BOW is smaller than 40 um, warp is smaller than 40 um, PLTV is larger than 95%, and the production process is suitable for mass production.

The invention discloses a method for processing a lithium niobate or lithium tantalate wafer, which comprises the following steps: respectively placing the lithium niobate or lithium tantalate wafer to be processed into a crucible; adding iron powder and lithium carbonate powder evenly mixed in advance according to mass proportion to completely cover the wafer; placing a corundum crucible into a thermal treatment furnace; performing thermal treatment for 3-20 hours at 450-550 DEG C under the nitrogen atmosphere with the flow rate of 0.5-1L/min to prepare a finished product of the lithium niobate or lithium tantalate wafer. The wafer resistivity is at the magnitude order of between 10 and 10, compared with the conventional non-processed wafer, the resistivity is greatly reduced, the method can effectively prepare a wafer needed for a SAW device through the thermal treatment in a short time, and increase a finished product ratio in the manufacture process of an element, therefore, the method for processing lithium niobate or lithium tantalite wafer becomes an industrialized optimizing method.

The invention relates to a refining process for lepidolite in tantalum-niobium ore waste rocks. A combined method with magnetic separation, high gradient magnetic separation, dense medium separation and flotation is adopted. The flotation adopts the process of rough flotation, dual fine flotations and sweeping. The process for refining the lepidolite from the granite-type tantalum-niobium ore waste rocks is provided. The tantalum-niobium ore waste rocks are crushed, screened, ground and subjected to high-frequency screening, spiral grading, permanent magnet magnetic separation for iron removal, high gradient magnetic separation, dense medium separation and flotation, so that lepidolite concentrates are obtained. By means of the method, the lepidolite concentrates are separated from the tantalum-niobium ore waste rocks. The lepidolite concentrates contain at least 4.5% of Li2O, at least 8.0% of K2O and Na2O and at most 0.10% of TiO2 and Fe2O3, the recovery rate of the lepidolite concentrates is larger than 80%, the qualities of the lepidolite concentrates meet the requirement of national standards, and the recovery rate of the lepidolite concentrates exceeds the industry level.

The invention provides a film bulk acoustic wave resonator prepared by employing ultrathin piezoelectric single crystals. The resonator comprises a high-resistance substrate with a ground chamber, and a sandwich active structure formed by clamping piezoelectrics through an upper metal electrode and a lower metal electrode. The sandwich active structure is arranged at the upper end of the high-resistance substrate. The piezoelectrics are ultrathin piezoelectric single crystals. A plurality of support posts are arranged in the ground chamber. The piezoelectric single crystals applied to the ultrathin piezoelectric single crystals are all practical piezoelectric single crystals, such as quartz, lithium tantalite, lithium tetraborate, bismuth germanate, bismuth silicate, lanthanum gallium silicate series, aluminium orthophosphate and potassium niobate. The high-resistance substrate is made of general substrate materials such as silicon, quartz, silicon carbide, aluminium oxide, sapphire and diamond in the microelectronic technology. The resonator has the advantages that the crystal completeness of the ultrathin piezoelectric single crystals is not damaged, and the ultrathin piezoelectric single crystals are perfect single crystals; the crystals and crystal orientation can be freely selected, and therefore the performance of the device is optimized; and the prospect of the production technology of the ultrathin piezoelectric single crystals is bright.

The invention provides a tantalum or niobium or tantalum and niobium alloy additive manufacturing method. The method comprises the following steps that firstly, tantalum powder or niobium powder or tantalum and niobium alloy powder is prepared for 3D printing; and secondly, the prepared tantalum powder or the prepared niobium powder or the prepared tantalum and niobium alloy powder for 3D printing is put into a 3D printer for printing, and then a tantalum or niobium or tantalum and niobium alloy metal product is prepared. By means of the manufacturing method, the cost of raw materials is low, the technological process is simple, the manufactured powder with good fluidity can be directly printed into metal products and artificial material implants according to design drawings or figures converted by scanning bones amputated by doctors, the production process is quick, and post-treatment workload is little.

The invention discloses a making method of a lithium tantalate black wafer. The method comprises the following steps: 1, weighing IV group nonmetal element powder and carbonate powder according to a certain ratio, and uniformly mixing the weighed powders to obtain an embedding material; 2, placing a lithium tantalate wafer to be processed in a crucible container, adding the embedding material to completely embed the wafer, and placing the crucible in a heat treatment furnace; 3, heating the lithium tantalate wafer to a heat insulation temperature in vacuum or inert or reducing flow atmosphere; 4, keeping the heat insulation temperature unchanged for 10-40 h; and 5, cooling the obtained wafer to room temperature after the heat insulation ends, and taking out the lithium tantalate wafer to obtain the black wafer. The method greatly reduces the electric resistivity of the wafer without influencing the piezoelectric performances or the single domain property of lithium tantalite, weakens and even eliminates the self pyroelectric effect of the wafer, enhances the absorption ability in the visible light region, and improves the lithography precision in the device making process.

The invention provides a method for preparing a high efficiency photocatalyst of nickel oxide supported tantalate, comprising the following steps: (1) uniformly dispersing tantalum oxide into excessive aqueous alkali and placing the mixture into a reaction kettle; (2) keeping the reaction kettle for a period of time at the set temperature to ensure full hydrothermal reaction; (3) after the hydrothermal reaction, fully washing and filtering the product in the reaction kettle until eluate is neutral, and preparing tantalate nano powder after drying; (4) uniformly dispersing certain amount of the tantalate nano powder into proper amount of nickel nitrate solution and evaporating the mixed solution at the constant temperature to obtain pressed powder; (5) putting ground pressed powder into a Muffle furnace for calcining to obtain the final product. The method adopts cheap raw materials and has simple equipment and process. The prepared photocatalyst of the tantalate has few structural defects, small grain size and good dispersibility, and the tantalate is endowed with good photocatalytic activity.

The invention belongs to the technical field of ceramic powder preparation, and discloses zirconium oxide/titanium oxide/cerium oxide doped rare earth tantalum/niobate RETa/NbO4 ceramic powder and a preparation method thereof. The zirconium oxide/titanium oxide/cerium oxide doped rare earth tantalum/niobate RETa/NbO4 ceramic powder has a chemical general formula being RE1-x(Ta/Nb)1-x(Zr/Ce/Ti)2xO4, wherein x is greater than 0 but smaller than 1. The crystal structure of the ceramic powder is an orthorhombic phase; the crystal lattice space group is C2221; the particle diameter is 10 to 70 mum;the ceramic powder is in a spherical shape. During the preparation, the raw materials are subjected to ball milling; then, after the reaction by a high-temperature solid phase method, a mixture is mixed with solvents and organic bonding agents to obtain slurry C; centrifugal atomization is performed to obtain dried particle materials; next, sintering is performed; the zirconium oxide/titanium oxide/cerium oxide doped rare earth tantalum/niobate RETa/NbO4 ceramic powder meeting the requirement of the APS (atmospheric plasma spraying) technology on the ceramic powder is obtained.

The invention discloses a preparation method for near-stoichiometric lithium tantalite crystal, which comprises the following steps: prepare the base material according to the molar ratio proportion of Li2CO3:Ta2O5=48-50:52-50; then add an alkali metal except Li2O as the flux; after grinding and mixing, heat to fully decompose and release CO2; calcine the mixture and get lithium tantalite polycrystalline charge; then press the polycrystalline charge, put in a crucible, heat to the fusion state, keep the temperature and then use the czochralski preparation method for the near-stoichiometric lithium tantalite crystal. The preparation method for near-stoichiometric lithium tantalite crystal has the advantages that: the process of preparing the near-stoichiometric lithium tantalite crystal is made simpler; the near-stoichiometric lithium tantalite crystal with bigger size and good uniformity is made easier to prepare; industrial mass production can be realized and the cost can be reduced.

The invention discloses phase-shifters, modulators, and method that produces a smaller π by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

The invention relates to a method for extracting tantalum and niobium through low alkali decomposition of a tantalum-niobium ore. According to the method, a small amount of sodium hydroxide is used as a melting agent for roasting decomposition of the tantalum-niobium ore to allow tantalum and niobium to be converted into sodium metatantalate and sodium metaniobate; and then, under the condition of addition of a conversion agent, tantalum and niobium in a roasting product are extracted with diluted hydrofluoric acid at a low temperature so as to obtain ore pulp containing fluotantalic acid and fluoniobic acid. The method provided by the invention has the advantages of simple process flow, small consumption of alkali, low cost and capacity of realizing nearly 100% of a tantalum-niobium ore decomposition rate.

This invention relates to a Czochralski method for growing tantalite crystal. The molecular formula of the grown compound is RE1-xDxTa1-yNbyO4, wherein, RE = Lu, Gd or Y; D = Bi, Ce, Eu or Tb; x and y = 0-1. The raw materials, Ta2O5, Nb2O5, Lu2O3, Gd2O3, Y2O3, Bi2O3, Eu2O3 and Tb4O7 are prepared from other compounds of Ta, Nb, Lu, Gd, Y, Bi, Eu and Tb. The Czochralski method comprises: mixing the raw materials, pressing in a mold into disc shape, and/or sintering at 750-1300 deg.C for 10-24 h to obtain the starting material for RE1-xDxTa1-yNbyO4 crystal. The method can obtain large-size single crystal of Nb5+, Bi3+, Tb3+ or Eu3+-doped RETaO4, which can be used in high-energy physics and nuclear medicine.

The invention provides a method for preparing sodium tantalate photo-catalyst powder by hydro-thermal method. The method comprises the following steps: using tantalum oxide and sodium hydroxide as raw material, adding water, preparing into solution, stirring fully in order to completely dissolve NaOH, dispersing Ta2O5 into the solution to form precursor solution, arranging the precursor solution into a reaction kettle, reacting at 120-180 DEG C for 12h by hydro-thermal method, cooling after the reaction is finished, taking the precipitate out of the reaction kettle, rinsing into neutrality with de-ionized water and anhydrous ethanol, and drying at constant temperature of 60 DEG C to obtain powder; carrying out photo-catalyzing reaction to the powder with rhodamine B as degradation material, wherein the degradation rate of rhodamine B is higher than 94 percent after 210min under the irradiation of ultraviolet light. The reaction temperature of the invention is low, that is about 140 degrees; and the prepared powder has good photo catalytic activity under the irradiation of ultraviolet light at 140 DEG C.

The invention belongs to the technical field of a moisture sensitive device, and in particular relates to a moisture-sensitive sensor based on a potassium tantalite sensitive membrane and a preparation method thereof. The sensor consists of a ceramic substrate, a gold (Au) metal interdigital electrode and a potassium tantalite sensitive membrane, wherein the Au metal interdigital electrode is prepared on the ceramic substrate by adopting a silk screen printing method, the potassium tantalite sensitive membrane is prepared on the Au metal interdigital electrode by adopting a coating method, the thickness of the potassium tantalite sensitive membrane is 2 to 4 micrometers, and both the width and the interval space of the metal interdigital electrode is 0.15 to 0.20mm. The preparation method comprises following steps of firstly adopting the silk screen printing method to prepare the Au metal interdigital electrode on the ceramic substrate, adopting a hydrothermal method to prepare a potassium tantalite sensitive material, adopting a coating method to coat the potassium tantalite sensitive material onto the metal interdigital electrode to prepare a moisture-sensitive element. The potassium tantalite moisture-sensitive sensor is simple in preparation process, small in size, applicable to mass production, high in sensitivity to the moisture, small in hysteresis, fast in responding time and vast in application value on the aspect of the moisture sensitive detection aspect.

The invention provides a preparation method of target-grade ultrahigh-purity tantalum metal. In the method, a recrystallization process is added in tantalum wet-process metallurgy, thereby effectively reducing the contents of high-melting-point metal impurities and radioactive elements. The preparation method comprises: industrial K2TaF7 is put in a pure diluted HF solution, the concentration of crystalline HF is controlled, the temperature of crystalline HF is controlled to 80-90 DEG C, and potassium salt is excessive by 5-10%; after naturally cooling to 35-45 DEG C, cooling water is introduced to cool to room temperature; filtration is carried out while washing with a solution having PH 9 and absolute ethyl alcohol, thus high-melting-point metals, transition metals and impurities such as uranium, thorium, carbon, oxygen and the like are effectively removed; and then in tantalum pyrometallurgy, Si is effectively removed, and the pollution of Fe, Ni and Cr is prevented; and low-melting-point metals of less than 3000 DEG C are further removed in tantalum refining, thereby effectively reducing the contents of C, N and O. By using the preparation method provided by the invention, therefining frequency of an electron beam furnace is saved, and production cost is reduced.