22 results about "Dielectric ceramics" patented technology

This application provides a temperature-stable low-dielectric silicate LTCC material and its preparation method, relating to the field of low-dielectric microwave dielectric ceramics technology. The low-dielectric silicate LTCC material has the following chemical formula: x Na2O- y CaO- z SiO2- m CaSnSiO5- n The compound of B2O3 was prepared, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.6≤ m ≤1.5, 0.03≤ n The dielectric constant is ≤0.1; the chemical formula of its main crystalline phase is Na2Ca2Si3O9. The temperature-stable low-dielectric silicate LTCC material prepared using the above method overcomes the defect of poor temperature stability in the synthesis of low-dielectric microwave dielectric ceramics in existing technologies. The prepared low-dielectric silicate LTCC material has the characteristics of low dielectric constant, temperature stability, and a sintering temperature below 950℃. It has the advantages of simple synthesis process, stable main crystalline phase composition, and low raw material price, making it a suitable low-dielectric LTCC material for millimeter-wave communication.

This application discloses a perovskite-structured high-entropy ceramic material with excellent dielectric temperature stability. The chemical formula of the high-entropy ceramic material is (Ca... 0.2 Sr 0.2 Ba 0.2 Mg 0.2 Bi 0.1 Na 0.1 (Ti1) x Zr x O3, x=0.05~0.2. This application employs an A-site high-entropy material composition design that enables elements to break through the solid solution limit, achieving greater solid solubility in the material system. By using Zr 2+ Ti at the B site in ion-substituted ceramics 2+ The composition design approach successfully achieved B-site ion doping, resulting in well-grown, dense grains within the ceramic. The sample microstructure exhibited few pores, with elements uniformly distributed throughout the ceramic without agglomeration. By optimizing and controlling the ceramic's microstructure, the dielectric ceramic obtained in this application possesses a high dielectric constant and excellent temperature stability, with capacitance-temperature variations meeting both X7R and X6R capacitor standards.

The application discloses a low-temperature sintering microwave dielectric ceramic material and a preparation method thereof, and relates to the technical field of microwave dielectric ceramics. In view of the defects that the existing low-temperature sintering technology cannot simultaneously consider low loss, high temperature stability and sufficient densification, the application adopts a niobium titanate solid solution with calcium partially replacing magnesium as a main phase, uses a silicon-zinc-boron-lanthanum quaternary system as a composite sintering agent, and prepares a finished product through pre-sintering, forming and 1100-1300 DEG C low-temperature sintering. The material realizes low signal transmission loss through the synergistic effect of main phase lattice optimization and the composite sintering agent, avoids glass phase flooding, improves the temperature stability and the densification degree, adapts to the requirements of medium and high capacity devices in terms of dielectric constant, is compatible with the existing mass production equipment in process, and has high performance and industrial feasibility.

This invention discloses a high-entropy rare-earth silicate ceramic powder and its preparation method. A flocculent precipitate is obtained through in-situ chemical co-precipitation via both forward titration (adding ammonium carbonate solution to a precursor solution) and reverse titration (adding the precursor solution to an ammonium carbonate solution). This precipitate is then repeatedly washed, dried, and calcined at high temperature to prepare a monoclinic high-entropy silicate powder. This invention arbitrarily selects five trivalent lanthanide rare-earth elements with different ionic radii and dissolves them into the high-entropy rare-earth silicate lattice, thereby significantly increasing the configurational entropy and lattice distortion of the sample, enhancing the phase structure stability, and resulting in a resonant frequency temperature coefficient closer to 0 ppm / ℃. The bulk sample of the high-entropy rare-earth silicate ceramic powder, after pressing and sintering, has a relative permittivity of 9.82~10.31, which meets the requirements for microwave dielectric ceramics in millimeter-scale communication.

The invention discloses a medium-entropy high-temperature dielectric ceramic and a preparation method thereof, and belongs to the technical field of functional ceramics, the chemical general formula of the ceramic material is (RE1, RE2, RE3) 3Al5O12, RE1, RE2 and RE3 are three different trivalent rare earth ions, and the key characteristic is that the ion radiuses of the three rare earth ions respectively belong to a large range, a medium range and a small range. According to the design, controllable maximum lattice distortion is introduced, the ion and electron polarizability of the material is remarkably enhanced on the premise that a garnet single-phase structure is not damaged, so that the intrinsic dielectric constant of the material is improved, and the medium entropy design ensures excellent high-temperature phase stability and dielectric property temperature stability of the material. The prepared medium-entropy high-temperature dielectric wave-absorbing ceramic can work in a high-temperature environment of 0-800 DEG C, not only has the characteristics of low heat conductivity and high temperature resistance, but also has excellent wave-absorbing performance in an X wave band, the lowest reflection loss of the medium-entropy high-temperature dielectric wave-absorbing ceramic can reach-58 GHz, and the effective absorption bandwidth of the medium-entropy high-temperature dielectric wave-absorbing ceramic can reach 2.8 GHz.

This invention discloses a wide-temperature stable, low-loss, high-dielectric ceramic material and its preparation method, relating to electronic functional ceramic materials. The method includes preparing the material according to the stoichiometric formula 0.9[(1- x Na 0.5 Bi 0.5 TiO3- x K 0.5 Bi 0.5 TiO3]-0.1LiTaO3,0.00≤ x ≤0.24, weigh Na 0.5 Bi 0.5 TiO3 powder, K 0.5 Bi 0.5 TiO3 powder and LiTaO3 powder are mixed evenly to form a complete feedstock. The feedstock is then ball-milled, dried, and sieved to form a sieved material. The sieved material is pressed into a green body, which is then sintered to obtain a wide-temperature stable, low-loss, high-dielectric ceramic. This solves the problems of high loss, low stability, large leakage current, and low breakdown field strength caused by high-temperature oxygen vacancy migration. The ceramic material prepared by this invention not only has high-temperature stability, high dielectric constant, and low dielectric loss and relaxation characteristics, but also has a simple preparation process, low material cost, and is environmentally friendly, making it an important candidate material that is both technically and economically superior to lead-based ceramic materials for high-end industrial applications.

The present application relates to the technical field of electronic information functional ceramic materials and electronic devices, and particularly relates to a method for forming dielectric ceramic by microwave rapid annealing treatment, which comprises the following steps: (1) sample pretreatment, (2) microwave annealing, (3) cooling and discharging. The present application breaks through the limitation of heat damage caused by traditional process, and realizes the repair of non-intrinsic defects and intrinsic defects in the ceramic body by high-power microwave second-level transient annealing under the premise of completely maintaining the original grain size, crystal structure and phase composition of the ceramic, thereby fundamentally avoiding the problems of abnormal grain growth and volatilization of low-melting-point components, and realizing the lossless and rapid repair of defects of the formed dielectric ceramic. The processing period of traditional annealing lasting for several hours is shortened to 1-10 s, the process time is greatly shortened, and the quality factor Qxf of the dielectric ceramic after treatment is improved by 30%-100% in the terahertz band, and the quality factor Qxf is improved by 30%-60% in the microwave band.

This invention relates to the field of dielectric ceramics technology, providing a glass-coated strontium titanate-based giant dielectric ceramic material and its preparation method. This invention utilizes a zinc borosilicate glass sol to coat strontium titanate-based ceramic powder, followed by pressing, aging, pulverizing, molding, debinding, and sintering to obtain the glass-coated strontium titanate-based giant dielectric ceramic material. This invention allows the glass sol to be uniformly distributed on the surface of the ceramic powder, forming a glass sol coating layer with a nanometer-thickness. After melting, the coating layer has almost no large pores, effectively improving the performance of the strontium titanate-based ceramic material. The glass-coated strontium titanate-based giant dielectric ceramic material prepared by this invention has a stable structure and good thermal stability, exhibiting a stable high dielectric constant and low dielectric loss over a wide temperature range, and can be widely used in the field of energy storage electronic materials.

This invention discloses a method based on O ‑ This paper discloses a CaTiO3-based giant dielectric ceramic material with an ion-mediated charge transfer mechanism and its preparation method, which relates to the field of electronic functional materials technology. The general structural formula of this ceramic material is Ca. 1‑1.5x La x TiO3, where x is 0.05~0.07; the preparation method of the ceramic material of the present invention is as follows: weigh CaTiO3, La2O3 and TiO2 raw materials according to the proportion and mix them to obtain a mixed raw material; ball mill, dry, stand and dry again to obtain powder; repeat the process of ball milling, drying, standing and drying again to obtain a precursor; grind the precursor and pre-fire it, the obtained powder is ball milled and dried twice, and then mixed with a binder and pressed into green sheets; after grinding and sieving the green sheets, they are pressed into blanks and left to stand; the blanks are debinded, sintered by gradient heating and cooled to finally obtain a ceramic material based on O ‑ CaTiO3-based giant dielectric ceramic materials with ion-mediated charge transfer mechanism. This invention utilizes O... ‑ Ion-mediated charge transfer mechanisms in La 3+ By introducing Ca vacancies into the doped CaTiO3 system, materials with giant dielectric properties are obtained.

The application belongs to the field of microwave dielectric ceramic and its manufacturing, and particularly relates to a non-stoichiometric Li3Mg2NbO6-BaV2O6 composite LTCC dielectric ceramic and a preparation method thereof, which is suitable for low-temperature co-fired ceramic LTCC microwave devices and radio frequency communication fields. Under the premise of not introducing additional fluxing agents, the low-temperature sintering characteristics and the positive temperature frequency coefficient characteristics of BaV2O6 are fully utilized to realize the synchronous regulation of the sintering temperature of Li3Mg2NbO6 ceramic and the temperature coefficient of resonant frequency, while maintaining a relatively high quality factor. Considering that the vanadium component is prone to volatilization loss at an isothermal region close to or higher than 700 DEG C and 800-900 DEG C, a non-stoichiometric rich addition measure is adopted to weaken the local non-stoichiometry and defect increase phenomenon caused by vanadium volatilization, so as to reduce the dielectric loss, further improve and stabilize the Qxf of the composite system, and improve the sample batch consistency.

The application discloses an ultralow-loss high-dielectric ceramic composition and relates to the technical field of ceramic materials, which comprises the following components in terms of molar fractions: 100 molar fractions of a perovskite compound containing Ba and Ti, 0.1-15 molar fractions of a compound containing Mg, 0.1-30 molar fractions of a compound containing Sr, 0.01-3 molar fractions of a compound containing Fe, and 0.1-6 molar fractions of an oxide containing R. The ultralow-loss high-dielectric ceramic composition disclosed by the application has ultralow dielectric loss and high dielectric constant.

A multilayer ceramic electronic component includes an element body, the element body including a capacitor section in which first and second internal electrode layers are alternately laminated with a dielectric layer interposed therebetween and protective regions of the capacitor section; and external electrodes provided on surfaces of the element body, the first and second internal electrode layers being drawn out from the surfaces, wherein each of the dielectric layer and the protective regions contains a dielectric ceramic as a main component, each of the protective regions includes a first layer adjacent to the capacitor section, a second layer adjacent to the first layer, and a third layer adjacent to the second layer, an atomic ratio of Mn in the second layer is larger than that in the first layer, and a content of a glass component of the second layer is larger than those of the first and third layer.

The application discloses a high-entropy tungstate microwave dielectric ceramic material and a preparation method thereof, and relates to the technical field of microwave dielectric ceramic materials. The preparation method of the high-entropy tungstate microwave dielectric ceramic material comprises the following steps: weighing raw materials and uniformly mixing the raw materials to form mixed raw materials; mixing grinding balls, a process control agent and the mixed raw materials, and ball milling to obtain mixed materials; after the mixed materials are dried, an adhesive is added for granulation, and then a green body is formed by pressing; the green body is subjected to four-stage temperature rising sintering, and then is cooled to room temperature in a furnace, so that the high-entropy tungstate microwave dielectric ceramic material is obtained. According to the high sintering temperature of the tungstate-based ceramic dielectric material, the microwave dielectric ceramic material is prepared by the method of multi-element solid solution effect, and the method has the advantages of simple operation, accurate control and high stability, and can be applied to the preparation field of microwave filters, resonators and other high-frequency electronic components for LTCC applications.

This invention discloses an A-site doped lead-free ceramic material, its preparation method, and its applications, relating to the field of dielectric ceramics technology. This invention simultaneously introduces multiple cations such as Sr, Ca, Bi, and Na into the A-site (Ba) of a barium titanate (BaTiO3) matrix to construct a high-entropy doped structure, effectively controlling lattice distortion and local polarization behavior, thereby obtaining excellent relaxor ferroelectric properties and high breakdown field strength. The material is prepared using an electrospinning combined with heat treatment process to form a nanofiber structure with a beaded morphology, significantly inhibiting abnormal grain growth, increasing density, and reducing defect concentration. The resulting ceramic exhibits high energy density, high energy storage efficiency, and excellent cycle stability over a wide temperature range. It is also free of toxic elements such as lead, making it environmentally friendly and suitable for high-temperature, high-power electronic devices in new energy vehicles, 5G communications, aerospace, and other fields, providing a reliable technical solution for developing next-generation high-performance lead-free energy storage capacitors.

Laminated ceramic capacitor comprising: a laminated body (10) comprising several layered dielectric ceramic layers (11) and several internal electrodes (12) provided at more than one interface between the dielectric ceramic layers (11); and an external electrode (13a, 13b) formed on an external surface of the laminated body (10) and electrically connected to the internal electrodes (12), wherein the laminated body (10) contains: a perovskite-like compound containing Sr, Ba, Zr, Ti and Ca, as well as Si; Mn; Al;and V, if a total fraction of Zr and Ti is considered to be 100 moles, the following relationship is satisfied: (a) a total fraction m (moles) of Sr, Ba and Ca satisfies 100 ≤ m ≤ 105, (b) a Si fraction a (moles) satisfies 0.1 ≤ a ≤ 4.0, (c) a Mn fraction b (moles) satisfies 0.1 ≤ b ≤ 4.0, (d) an Al fraction c (moles) satisfies 0.01 ≤ c ≤ 3.0, (e) a V fraction d (moles) satisfies 0.01 ≤ d ≤ 0.3, (f) a molar ratio w (Sr / (Sr + Ba + Ca)) of the sum of Sr, Ba and Ca to Sr satisfies 0.60 ≤ w ≤ 0.95,(g) a molar ratio y (Ca / (Sr + Ba + Ca)) of the sum of Sr, Ba and Ca to Ca satisfies 0 ≤ y ≤ 0.35,(h) a molar ratio z (Zr / (Zr + Ti)) of the sum of Zr and Ti to Zr satisfies 0.92 ≤ z ≤ 0.98,a sum of a value of w and a value of y satisfies 0.6 ≤ w + y ≤ 0.95 and the several dielectric ceramic layers (11) each have crystal grains and the crystal grains have an average grain size of 1.2 µm or less.;

A dielectric ceramic composition which is a dielectric ceramic composition containing forsterite as a main component and containing a glass component as a subcomponent, wherein the glass component contains lithium, calcium, barium, and silicon, and the glass component is added in an amount of 12 parts by weight or more with respect to 100 parts by weight of the main component.

This invention discloses a method for preparing composite solid electrolyte materials from high dielectric ceramic powder and its synthesis, belonging to the field of battery technology. The method includes the following steps: (1) adding ceramic powder to a first solvent and stirring evenly to obtain a first solution; (2) adding polymer solid electrolyte and lithium salt to a second solvent and stirring evenly to obtain a second solution; (3) mixing the first solution and the second solution evenly to obtain a dispersion; (4) electrospinning or casting the dispersion and drying it to obtain a solid electrolyte membrane. This invention adds specific ceramic powder to a first solvent and then mixes it with a second solution containing polymer solid electrolyte and lithium salt to obtain a dispersion. Electrospinning is then performed on the dispersion to obtain a solid electrolyte membrane. The ceramic powder can be evenly dispersed in the system, effectively reducing the crystallinity of the polymer solid electrolyte, effectively increasing the ionic conductivity, effectively increasing the lithium ion transference number, and effectively improving the cycle performance.

The invention relates to the technical field of composite dielectric materials and high-frequency devices, and particularly discloses a high-strength and low-dielectric ceramic composite material and a preparation method and application thereof. The ceramic composite material is of a composite layered structure and comprises a functional layer and at least one substrate layer, the dielectric constant of the functional layer at the frequency of 20GHz is not greater than 5.0; the bending strength of the substrate layer is greater than or equal to 200MPa; the substrate layer and the functional layer are integrally sintered and molded through a low-temperature co-fired ceramic process, and the sintering shrinkage deviation of the substrate layer and the functional layer is less than or equal to 3%. The overall bending strength of a ceramic composite material system reaches 200 Mpa or above, the strength is close to that of a conventional LTCC (low temperature co-fired ceramic) product, and the electrical property of a functional layer is not affected. The working frequency band of the millimeter wave filter prepared based on the system can reach 20GHz and above, and the insertion loss is less than or equal to 0.8 dB.

The application discloses A and B site doped BaTiO3-based dielectric ceramic, characterized in that the chemical formula of the A and B site doped BaTiO3-based dielectric ceramic is (Ba x1 Ca x2 Sr 1‑x1‑x2 )(Ti 0.4 La 0.2 Ce 0.2 Ta 0.2 )O3, 0≤x1≤1, 0≤x2≤1, and x1+x2≤1. The application also discloses a preparation method thereof. The application introduces other elements into A and B of the barium titanate ceramic dielectric material, improves the high-temperature stability and energy storage performance, and overcomes the defects of poor temperature stability and low energy storage efficiency of the existing barium titanate ceramic dielectric material.

This invention relates to a flexural electric thin film, its preparation method, and its applications. One flexural electric thin film comprises: a flexible polymer matrix and fillers dispersed within the flexible polymer matrix, wherein the fillers are high-dielectric ceramic nanoparticles; the mass concentration of the high-dielectric ceramic nanoparticles exhibits a gradient distribution along the thickness direction of the flexible polymer matrix. The gradient distribution can be a continuously varying gradient distribution or a stepwise variation in the mass concentration of the high-dielectric ceramic nanoparticles. This invention, by constructing a built-in material property gradient, transforms external uniform bending strain into non-uniform strain within the material, amplifying the strain gradient source driving the flexural electric effect and resulting in an order-of-magnitude improvement in the macroscopic flexural electric response.