562results about How to "High curie temperature" patented technology

The invention relates to a high capacity low power consumption manganese-zinc ferrite material manufacturing method. The constituents includes 69.1-72.5wt% Fe₂ O₃, 22-24wt% Mn₃O₄, and ZnO. In the process of grinding and sintering, two or more from TiO₂, Gd₂ O₃, SnO₂, Co₂O₃, Ta₂O₅, Nb₂O₅, CaCO ₃ could be added into the raw material. After grinding, pressure molding, sintering following certain temperature curve, the manganese-zinc ferrite material would be gained. The invention is simple and cost low. It has the feature of wide bandwidth and wide temperature.

The invention discloses a ternary system relaxation ferroelectric single crystal material. The material comprises the following chemical components: xPb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-(1-x-y)PbTiO3, wherein the x is equal to 0.1-0.45, and the y is equal to 0.1-0.5. A preparation method of the single crystal material PIMNT is an improved Bridgman method and comprises the following steps of: processing raw materials, melting by raising the temperature, and performing crucible degrowth and crystal cooling growth. The prepared single crystal material overcomes the defects of over low Curie point of PMNT single crystals, difficult crystallization and difficult batch growth of the PINT single crystals in the prior art, has high piezoelectric performance and pyroelectric performance, higher temperature stability and wide application prospect and adds a new product in the field.

The invention belongs to the field of soft magnets, and particularly provides a soft-magnetic nickel-copper-zinc ferrite material which comprises major components and minor components, wherein the major components comprise the following components in percentage by mol: 46.5-50.0 mol% of Fe2O3, 12.0-17.0 mol% of NiO, 27.0-31.0 mol% of ZnO and 4.0-8.0 mol% of CuO; and the minor components comprise manganese oxide and bismuth oxide, wherein on the basis of the total weight of the major components, the total weight percent of the minor components and standard substances thereof MnO and Bi2O3 is 0.1-1.0 wt%. Under the wide frequency of 50 KHz-10 MHz and especially high frequency of 1 MHz-10 MHz, the material provided by the invention has the characteristics of high magnetic conductivity (mu i is approximately equal to 300, and f is equal to 1 MHz), high resistivity, low specific loss, low specific temperature coefficient and the like.

The invention discloses a bismuth scandate-lead titanate high-temperature piezoelectric ceramic material. The bismuth scandate-lead titanate high-temperature piezoelectric ceramic material comprises a matrix with the chemical formula of xBiScO3-(1-x)PbTiO3 and bismuth trioxide (Bi2O3) in an amount which is less than 0.4 percent of the total weight of the matrix. The bismuth scandate-lead titanate high-temperature piezoelectric ceramic material is prepared by adding excess Bi2O3 into raw materials of Sc2O3, Bi2O3, Pb3O4 and TiO2 in the metering ratio according to the chemical formula of xBiScO3-(1-x)PbTiO3, wherein x is 0.35 to 0.38; and the using amount of the excess Bi2O3 is 0.1 to 0.4 percent of the total weight of the raw materials of Sc2O3, Bi2O3, Pb3O4 and TiO2 in the metering ratio according to the chemical formula of xBiScO3-(1-x)PbTiO3. The bismuth scandate-lead titanate high-temperature piezoelectric ceramic material solves the problems that ceramic sintering temperature is increased and piezoelectric and dielectric properties are reduced due to deviation of a stoichiometric ratio caused by bismuth volatilization in the sintering process of BSPT ceramic, and has high Curie temperature, excellent piezoelectric property and an actual application value in high-temperature electronic equipment. The invention also discloses a preparation method for the bismuth scandate-lead titanate high-temperature piezoelectric ceramic material. In the preparation method, the piezoelectric ceramic material is prepared by synthesizing and sintering at lower temperature, so production cost is reduced, process steps are simplified, and the material has actual application value.

A dielectric ceramic including a perovskite compound represented by the general formula {(Ba_1-x-yCa_xSn_y)_m(Ti_1-zZr_z)O₃} as a primary component in which the x, y, z, and m satisfy 0.02≦x≦0.20, 0.02≦y≦0.20, 0≦z≦0.05, and 0.99≦m≦1.1 and is processed by a thermal treatment at a low oxygen partial pressure of 1.0×10⁻¹⁰ to 1.0×10⁻¹² MPa. Accordingly, there are provided a dielectric ceramic which can be stably used in a high-temperature atmosphere without degrading dielectric properties, properties of which can be easily adjusted, and which generates no electrode breakage even when ceramic layers and conductive films are co-fired, and a ceramic electronic element, such as a multilayer ceramic capacitor, which uses the above dielectric ceramic.

The invention relates to a high frequency nickel-copper-zinc ferrite and a method for preparing the same, which belong to the technical field of nickel series soft magnetism ferrite. The main components of the ferrite are ferric oxide, nickel oxide, zinc oxide, and copper oxide, the accessory components comprise cobalt oxide, bismuth oxide, and silicon oxide, and the ferrite is prepared by an oxide method. The invention adopts an iron deficiency formulation, a low calcination temperature, and a low sintering temperature so that the prepared high frequency nickel-copper-zinc ferrite has good performances of low initial permeability, low relative dissipation factor between 50MHz and 200MHz, and high Curie temperature, and can better satisfy the use requirement of communication electronic parts and components; besides, the preparation process is stable, and the production process has low energy consumption.

The invention provides a method for preparing a composite sintered neodymium-iron-boron permanent magnet material added with gadolinium, holmium and yttrium. The method includes the steps of primary batching, fusion casting, milling, secondary batching, powder mixing, forming, sintering and heat treatment, wherein in the primary batching step, iron alloy added with three rare earth elements of the gadolinium, the holmium and the yttrium is composited, and in the secondary batching step, oxide added with the three rare earth elements of ultrafine gadolinium, holmium and yttrium and cuprous oxide powder are composited. By the method, the relative surplus and cheap gadolinium, holmium and yttrium can be used for partially substituting for rare earth elements of neodymium, praseodymium or dysprosium, and accordingly neodymium, praseodymium or dysprosium consumption can be decreased by 10-30wt.%. Besides, Curie temperature and coercivity force of the prepared neodymium-iron-boron permanent magnet material are increased, corrosion resistance is enhanced, operating temperature and toughness are increased, and processability is improved.

The invention discloses a crystal boundary diffusion method for improving the coercive force and the thermal stability of a neodymium-iron-boron magnet, and belongs to the field of rare earth permanent magnet materials. According to the method, a quaternary alloy Dy-Ni-Al-Cu with a low melting point is used as a diffusion source and melted and prepared into a rapid-hardening strip, after coarse breaking, the strip casting is laid around the neodymium-iron-boron magnet, and by the adoption of a heat treatment method, the rapid-hardening strip diffuses and enters the magnet along the crystal boundary. After the processing, the coercive force of the magnet is significantly improved, and the magnetic energy product is improved to a certain extent; meanwhile, since the temperature of the diffusion treatment is low, energy consumption can be reduced, the cost can be lowered, and Nd2Fe14B crystal grains can be prevented from growing up; compared with a coating and magnetron sputtering method, the crystal boundary diffusion method omits a powder preparing and coating process in a coating technology and a thin film preparing process in a magnetron sputtering technology. After the technology processing of the crystal boundary diffusion method, the neodymium-iron-boron magnet with the high coercive force and the high thermal stability is finally obtained.

The invention belongs to the field of soft-magnetic ferrite materials. The objective of the invention is to provide a soft-magnetic nickel-copper-zinc ferrite material and a preparation method thereof. The material provided by the invention comprises major components and minor components. The major components comprise the following raw materials in mole percentage: 47.0-49.0mol% of Fe2O3, 17.5-18.5mol% of NiO, 26.0-29mol% of ZnO and 6.0-7.0mol% of CuO. The minor components comprise, based on the total weight of the major components, 0.1-0.40% of MnO, 0.1-0.5% of Bi2O3 and 0.3-0.5% of Co2O3. Under a high frequency of 13.56 MHz, the material provided by the invention has the characteristics of high magnetic conductivity ([mu]' is approximately equal to 130), low complex magnetic permeability [mu]''(namely low loss), high resistivity, high Curie temperature, high saturation magnetic induction density Bs, and the like.

A piezoelectric ceramic 1 in a piezoelectric element 20 contains, as a major component, a composition containing one or more complex oxides with metal elements other than lead as constituent elements. At least one of the complex oxides includes an alkali metal and Nb as constituent elements. Also, either or both of the elements Mn and Cu are segregated at the grain boundaries of the composition.

The invention belongs to the technical field of magnetic materials, and discloses a high-stability garnet microwave ferrite magnetic sheet and a preparation method thereof. The material composition ofthe high-stability garnet microwave ferrite magnetic sheet is Y<3-f-2d-a>Gd<f>Ca<2d+a>Bi<e>Fe<5-a-b-c-d-sigma>SnInMn<c>V<d>O<12>, wherein a is more than 0 and no more than 0.7; b is more than 0and no more than 0.7; c is more than 0 and no more than 0.6; d is more than 0 and no more than 1.5; e is more than 0 and no more than 0.6; f is more than 0 and no more than 0.8; and sigma is more than 0 and no more than 0.4. According to the high-stability garnet microwave ferrite magnetic sheet, Bi<3+> ions are added into the material, so the dielectric constant of the material is improved, anda Curie temperature is increased; and in addition, SnO<2>, In<2>O<3>, SnO<2> and In<2>O<3> are added into the material, so the anisotropy coefficient K of the material can be reduced, and the ferromagnetic resonance linewidth Delta(H) of the material is reduced. In terms of the process, high-pressure sintering is adopted to replace normal-pressure sintering, so sintering density is improved, the porosity of the material is reduced, and the ferromagnetic resonance linewidth Delta(H) of the material is reduced. Thus, the problem that the temperature coefficient of the material is poor is solved,and the material is guaranteed to have low ferromagnetic resonance linewidth Delta(H), high dielectric constant and high Curie temperature.