353 results about "Dielectric ceramics" patented technology

The invention belongs to the field of microwave communication, and relates to a double-frequency microstrip circulator based on multi-layer material nesting, and the circulator comprises a substrate, a magnetic conductive sheet, a high dielectric ceramic, a high dielectric constant ferrite ring, a high magnetic saturation ferrite, a circuit layer, a ceramic sheet, and a permanent magnet. The magnetic conductive sheet is arranged at the bottom of the base body, the high-dielectric ceramic is arranged on the magnetic conductive sheet, the high-dielectric-constant ferrite ring is annularly embedded in the high-dielectric-constant ceramic, and the high-magnetic-saturation ferrite is embedded in the high-dielectric-constant ferrite ring. The circuit layer is arranged on the substrate consisting of the high dielectric ceramic, the high dielectric constant ferrite ring and the high magnetic saturation ferrite, the ceramic chip is arranged on the circuit layer, and the permanent magnet is arranged on the ceramic chip. The overall size is small, weight is light, and reliability is high; the working frequency range is wide, through different transformations, the system is not easily detected by enemies, the confidentiality is high, and the anti-interference capability is strong; the method can be widely applied to the fields of mobile communication, satellite communication, radar detection, electronic countermeasures and the like.

The present invention belongs to the technical field of microwave dielectric ceramics, and discloses a reducing-resistant microwave dielectric ceramic temperature-frequency characteristic regulator. Among them, the application of a microwave dielectric ceramic material as a microwave dielectric ceramic temperature-frequency characteristic regulator, and the chemical formula of the microwave dielectric ceramic material satisfies (AO)3(BO)(XO2)2, where A = Ba x Sr y , B = Mn h Mg k , X = Si m Ti n ; x + y = 1, h + k = 1, m + n = 1, 0 ≤ x ≤ 1, 0.6 ≤ h ≤ 1, 0.8 ≤ m ≤ 1; and when h = 1 and m = 1, x ≠ 0; this microwave dielectric ceramic material can be adjusted by addition to regulate the overall temperature coefficient of resonance frequency of the ceramic system. By improving the composition of the material, the obtained microwave dielectric ceramic material has the characteristics of adjustable dielectric constant, low dielectric loss, and high positive temperature coefficient of resonance frequency, and can especially be used as a microwave dielectric ceramic temperature-frequency characteristic regulator with a strong regulation effect.

The invention relates to the technical field of dielectric ceramics, and provides a gadolinium-tantalum co-doped strontium titanate-based giant dielectric ceramic material and a preparation method thereof. The gadolinium-tantalum co-doped strontium titanate-based giant dielectric ceramic material is obtained by co-doping a strontium titanate material with gadolinium and tantalum and sintering under a nitrogen condition. The gadolinium-tantalum co-doped strontium titanate-based giant dielectric ceramic material prepared by the method is stable in structure, grains are refined and grow more compactly through nitrogen atmosphere sintering, the types of defect structures in the material are richer through a double-element doping and atmosphere sintering process, and the dielectric property of the strontium titanate-based giant dielectric ceramic material is improved. The result of the embodiment shows that when x is equal to 0.015, the dielectric constant of the gadolinium-tantalum co-doped strontium titanate-based giant dielectric ceramic material is 320926 and the dielectric loss is 0.1119 at the room temperature and the test frequency of 1kHz.

The invention discloses a high-dielectric composite material and a preparation method thereof, and belongs to the technical field of composite materials. The preparation method comprises the following steps: mixing and grinding dielectric ceramic powder and polymer particles at the temperature of-200 DEG C to-100 DEG C, so that the dielectric ceramic powder is coated on the surfaces of the polymer particles or dispersed among the polymer particles to obtain a pre-mixture; and carrying out hot pressing treatment on the pre-mixture to obtain the high-dielectric composite material with the isolation structure. According to the preparation method, the polymer-based composite material with the isolation structure is obtained through the preparation steps of combining low-temperature grinding and mixing with hot pressing, the dielectric ceramic powder is regularly and continuously enriched in a composite material matrix through the isolation structure, the dielectric constant of the composite material can be greatly improved, and the preparation method is simple in process, low in cost and free of pollution.

The invention discloses an A and B site doped BaTiO3-based dielectric ceramic, which is characterized in that the chemical formula of the A and B site doped BaTiO3-based dielectric ceramic is (Bax1Cax2Sr1-x1-x2) (Ti0. 4La0. 2Ce0. 2Ta. 2) O3, 0 < = x1 < = 1, 0 < = x2 < = 1, and x1 + x2 < = 1. The invention also discloses a preparation method of the composition. Other elements are simultaneously introduced into A and B of the barium titanate ceramic dielectric material, so that the high-temperature stability of the barium titanate ceramic dielectric material is improved, the energy storage performance of the barium titanate ceramic dielectric material is also improved, and the defects that an existing barium titanate ceramic dielectric material is poor in dielectric property temperature stability and low in energy storage efficiency are overcome.

The invention provides a sandwich multi-layer high-entropy lead-free dielectric material and a preparation method thereof, belongs to the technical field of energy storage ceramics, and aims to solve the technical problems that multi-layer ceramics are not compact in sintering, low in breakdown-resistant field strength and relatively low in energy storage performance. The sandwich multilayer high-entropy lead-free dielectric material comprises an upper dielectric layer, a lower dielectric layer and a middle high-entropy dielectric ceramic layer, the upper dielectric layer and the lower dielectric layer are both made of Mg2SiO4, and the high-entropy dielectric ceramic layer is made of Ba < 0.2 > Sr < 0.2 > Na < 0.2 > Bi < 0.2 > Ca < 0.2 > Ti < 0.25 > Ti < 0.25 > Nb < 0.25 > Zr < 0.25 > Mg < 0.25 > O < 3 >. The sandwich multi-layer high-entropy lead-free dielectric material prepared by the method has relatively high density, relatively high breakdown-resistant field strength, relatively high dielectric property, relatively high energy storage density and good discharge efficiency, the breakdown-resistant field strength reaches 1200 kV / cm, the maximum energy storage density reaches 6 J / cm < 3 >, and meanwhile, the sandwich multi-layer high-entropy lead-free dielectric material has relatively good temperature stability. The method has the advantages of simplicity, feasibility, low cost, convenience, rapidness, large-scale production and the like.

The invention provides a high-dielectric low-loss ceramic composition as well as a preparation method and application thereof, and relates to the technical field of functional ceramic materials, the high-dielectric low-loss ceramic composition comprises a perovskite type compound serving as a main component and an auxiliary component; wherein the perovskite type compound contains a Ba element and a Ti element, and the auxiliary components comprise a first auxiliary component containing an Mg element, a second auxiliary component containing an Nb element, a third auxiliary component containing an Mn element, a fourth auxiliary component containing a rare earth element R, and a fifth auxiliary component containing SiO2. According to the present invention, the ratio of the main components to the auxiliary components is subjected to design optimization, the ratio of the Nb element in the second auxiliary component to the Mn element in the third auxiliary component is adjusted, and the material preparation process parameters are subjected to optimization control, such that the dielectric constant and the temperature stability of the dielectric ceramic material are improved, and the dielectric loss is reduced.

The invention discloses an Mg + Nb co-doped TiO2 giant dielectric ceramic material and a preparation method thereof, and relates to the technical field of giant dielectric materials. The (Mg + Nb) co-doped TiO2 ceramic is successfully prepared by adopting a traditional solid phase method, the performance of the TiO2-based giant dielectric ceramic is regulated and controlled through a new doping strategy, the raw material is single, the preparation process is simple, the cost is low, the repeatability is good, the yield is high, the obtained ceramic material has giant dielectric performance, and the preparation method is suitable for industrial production. The (Mg + Nb) co-doped TiO2 novel giant dielectric ceramic can meet the requirements of a dielectric material with high dielectric constant, low dielectric loss and good temperature and frequency stability, and compared with other widely applied giant dielectric materials, the titanium dioxide-based giant dielectric ceramic has the characteristics of simplicity in preparation and excellent dielectric property.

The invention relates to the technical field of dielectric ceramic powder preparation processes, in particular to a multilayer ceramic capacitor, high-activity nano barium titanate powder for the multilayer ceramic capacitor and a preparation method of the high-activity nano barium titanate powder, and the method comprises the following steps: (1) reacting soluble barium salt with a precipitator to obtain barium carbonate precursor particles with high specific surface area; (2) uniformly coating the surfaces of the barium carbonate precursor particles with nano titanium dioxide particles by using a supercritical fluid flash evaporation technology to form a composite precursor; and (3) carrying out solid-phase synthesis reaction on the composite precursor, and sintering to obtain the nano barium titanate powder. Through the synergistic effect of two means of high-activity precursor preparation and nanoscale uniform coating, the composite precursor with extremely high specific surface area, surface energy and microcosmic uniformity is prepared, the thermal sintering temperature is effectively reduced, abnormal growth of crystal grains and lattice distortion are restrained, and the preparation method has the advantages that the preparation process is simple, and the preparation cost is low. The tetragonality of the nano barium titanate powder is obviously improved.

The present application relates to the technical field of dielectric ceramic powder preparation, and particularly relates to a multilayer ceramic capacitor, a high-activity nano-barium titanate powder for the multilayer ceramic capacitor and a preparation method of the high-activity nano-barium titanate powder, the method comprising the following steps: (1) reacting a soluble barium salt with a precipitator to obtain barium carbonate precursor particles with high specific surface area; (2) uniformly coating nano-titanium dioxide particles on the surface of the barium carbonate precursor particles by using a supercritical fluid flash technology to form a composite precursor; and (3) performing a solid-phase synthesis reaction on the composite precursor and sintering to obtain nano-barium titanate powder. The present application, through the synergistic effect of the two means of "high-activity precursor preparation" and "nano-level uniform coating", prepares a composite precursor with extremely high specific surface area, surface energy and micro-uniformity, effectively reduces the heat sintering temperature, suppresses abnormal grain growth and lattice distortion, and significantly improves the tetragonality of the nano-barium titanate powder.

The invention discloses a preparation method of high-capacity X7R type barium titanate-based dielectric ceramic powder, and relates to the field of preparation of barium titanate-based electronic materials, and the preparation method comprises the following steps: pre-synthesizing a rare earth-transition metal composite dopant by adopting a sol-gel method; mixing the obtained rare earth-transition metal composite dopant with a 100-250 nm solid-phase nano barium titanate main material, and adding a glass phase sintering aid; a staged pre-sintering process is adopted; ball-milling the pre-sintered powder by a high-energy ball mill, and sintering in a microwave-assisted atmosphere sintering furnace by adopting a microwave-assisted atmosphere sintering process; according to the design of the composite dopant, atomic-scale uniform doping of rare earth and transition metal is achieved through a sol-gel method, and the problem of component segregation caused by traditional mechanical mixing is solved; a staged pre-sintering process is adopted and is different from traditional single-stage pre-sintering, organic matters are removed in a low-temperature stage to avoid carbon residues, and the grain size is accurately controlled in a high-temperature stage; a contrast experiment shows that the dielectric constant is increased by 15%.

The invention relates to the technical field of ceramic materials, in particular to a high-temperature impedance X7R dielectric ceramic material and a preparation method and application thereof.The high-temperature impedance X7R dielectric ceramic material is prepared from main powder, a doping agent, a dispersing agent and a binding agent, the main powder is prepared from BaTiO3 and Na0. 5Bi0. 5TiO3 according to the molar ratio of 9: 1 through ball milling and presintering, the presintering temperature ranges from 1200 DEG C to 1400 DEG C, and the presintering time ranges from 2 h to 4 h; the doping agent is obtained by pre-sintering Nb2O5, transition metal oxide MeO and MgCO3, the pre-sintering temperature is 650 to 750 DEG C, and the pre-sintering time is 1 to 2 hours; the main powder is 100 parts by mole, the Nb2O5 is 0.1 to 1.0 part by mole, the MgCO3 is 0.1 to 1.0 part by mole, and the transition metal oxide MeO is 0.1 to 3.0 parts by mole. The temperature characteristic of the dielectric ceramic is improved, and the temperature stability of the dielectric ceramic meets the X7R dielectric material standard formulated by the American Electronic Industry Association.

The invention discloses a composite solid electrolyte membrane, a preparation method thereof and a lithium ion solid-state battery, and belongs to the technical field of batteries. The composite solid electrolyte membrane comprises inorganic fibers, lithium salt and a polymer film-forming matrix. The inorganic fiber comprises a dielectric ceramic fiber and an inorganic ion conductive fiber which are formed by side-by-side electrostatic spinning. Under an external electric field, a built-in electric field can be generated between the dielectric ceramic fiber and the inorganic ion conductive fiber which are formed by side-by-side electrostatic spinning, a space charge layer between the organic polymer solid electrolyte and the inorganic ion conductive material in the composite solid electrolyte membrane can be weakened, and the lithium flux is optimized, so that dissociation of lithium ions is promoted; the composite solid electrolyte membrane can generate more lithium ions easy to move, so that the lithium ions in the lithium salt can spontaneously transfer to the inorganic ion conductive material in a cross-interface manner, thereby realizing high-efficiency transmission of the lithium ions and further improving the ionic conductivity of the composite solid electrolyte membrane.

The invention provides a high-dielectric-constant NP0 type dielectric ceramic material as well as a preparation method and application thereof. The high dielectric constant NP0 type dielectric ceramic material is prepared from the following raw materials: 15 mol% to 16 mol% of BaCO3 and / or BaO, 2 mol% to 6 mol% of Nd2O3, 2 mol% to 6 mol% of Sm2O3, 5 mol% to 10 mol% of Bi2O3 and 55 mol% to 70 mol% of TiO2. The ceramic dielectric material provided by the invention has medium sintering temperature, high dielectric constant, low dielectric loss and high insulation resistance, and meets the specification requirements of NP0 type dielectric ceramics.

The invention relates to the technical field of ceramic capacitors, in particular to an X6S characteristic high-capacity multilayer chip ceramic capacitor and a preparation method thereof, the capacitor is formed by overlapping a dielectric ceramic layer and an inner electrode, and two ends of the capacitor are provided with outer electrodes which are connected with the inner electrode. The dielectric ceramic layer is formed by the dielectric ceramic material. According to the preparation method, barium titanate particles with specific average particle size, a doping agent with specific composition and specific preparation conditions are utilized to prepare the multilayer chip ceramic capacitor. Compared with the prior art, the dielectric material and the corresponding capacitor have both X6S characteristic temperature stability and high capacity, and still have high IR characteristic and low dielectric loss factor (tan delta) even in a high-temperature environment.

The invention discloses integrated equipment and method for preparing a ferrite-microwave dielectric ceramic composite substrate by using a flash Joule thermal method. The integrated equipment comprises a central control system, an identification camera, a path planning system, a Joule heating system, a base station, a preheating system, a reaction chamber and a conductive clamp. The central control system is mainly used for storing process parameters, receiving scanning signals and sending commands; the path planning system executes a command planning path set by the central system; the Joule heating system is used for charging and discharging a capacitor and is connected with the central control system to release electricity for positive and negative electrodes in real time; a resistance wire is wrapped outside the base to preheat the material, copper wires are arranged at the bottom of the base in a manner of penetrating through array apertures, and a copper sheet is welded at the upper part to improve the conductive area; quartz glass is arranged outside the reaction chamber, the upper cover plate and the lower cover plate can axially move to fix the reaction position, and the conductive clamp is used for non-conductive ferrite materials. According to the invention, the ferrite and the microwave dielectric ceramic can be quickly connected to prepare the composite substrate with excellent electromagnetic performance.

The invention relates to the technical field of microwave ferrite devices, and discloses a miniaturized broadband microstrip circulator based on a double-ferrite nested structure, comprising a substrate, the upper surface of which is provided with a magnetic conductive sheet; a high dielectric ceramic is arranged on the magnetic conductive sheet, and a low magnetic saturation ferrite and a high magnetic saturation ferrite are sequentially nested in an inner cavity of the high dielectric ceramic; a circuit is arranged on the upper surface of the high-dielectric ceramic, and a ceramic piece and a permanent magnet are sequentially installed above the circuit. According to the circulator, a magnetic conductive sheet is additionally arranged, a structure with high dielectric ceramics as a core is constructed, the characteristic difference of two ferrite gyromagnetic materials with different magnetic saturation intensities is utilized, and the frequency resonance characteristic of a center junction is adjusted through nested arrangement, so that gyromagnetic effects under different frequencies are complementary to expand the working frequency band. Meanwhile, the high-dielectric ceramic optimizes port impedance matching and reduces electromagnetic wave reflection by virtue of a high dielectric constant, and cooperates with an internal ferrite nested structure, so that the frequency bandwidth is widened through a composite material mode, and miniaturization and broadband effects are achieved.

A method for manufacturing a multi-layer ceramic capacitor (MLCC) end electrode and printing a full-area inner electrode protective layer is disclosed. The method uses thin dielectric ceramic layer thickness and a plurality of nickel inner electrode stacks to achieve high capacitance. The method produces high-density electrode-to-ceramic ratio end edges and side edges. The method uses an ultralow-temperature electrochemical deposition coating technology to manufacture a low-stress multi-layer ceramic capacitor end electrode and an insulating protective layer, thereby improving the yield of the multi-layer ceramic capacitor and reducing manufacturing costs.

The invention discloses an electrostatic chuck, and belongs to the technical field of semiconductors, and the electrostatic chuck comprises a ceramic substrate which comprises a main adsorption surface used for adsorbing a wafer; the adsorption electrode is embedded in the ceramic substrate, the adsorption electrode comprises a metal conductive material and other materials used for generating a liquid phase to promote sintering, and the addition amount of the other materials is 0.2 wt%-1.5 wt% relative to the addition amount of the metal conductive material; the average grain size of the other materials is smaller than the average grain size of the ceramic substrate. In the application, the average grain size of other materials is set to be smaller than the average grain size of the ceramic substrate, so that the grain sizes of the adsorption electrode are different, on one hand, the conductivity of the adsorption electrode is not influenced, and on the other hand, the adhesion between the adsorption electrode and the dielectric ceramic can be obviously improved; the problem of poor adhesion between the adsorption electrode and the dielectric layer of the high-purity alumina electrostatic ceramic disc can be effectively improved.

To provide an additive for producing dielectric ceramics which can easily realize a state of atomized powder, has low hygroscopicity, and can realize high density of dielectric ceramics.SOLUTION: An additive for producing dielectric ceramics is a composite powder comprising an alkaline earth metal element A and boron, and in the composite powder, the molar amount a of the alkaline earth metal element A and the molar amount b of the boron satisfy the following formula (1). The composite powder satisfies at least one condition selected from the group consisting of the following condition (i) and the following condition (ii). (i) The composite powder includes an amorphous phase. (ii) The composite powder includes two or more crystal phases.SELECTED DRAWING: Figure 4

A dielectric ceramic composition includes main phase grains and a grain boundary between the main phase grains. The main phase grains include a perovskite compound as a main component. The perovskite compound includes at least Ca and Sr as A-site elements and at least Zr and Ti as B-site elements. The dielectric ceramic composition further includes an oxide of at least one additional element. β / α is 3.0 or more and 6.0 or less, where α (unit: parts by mol) denotes a content of the at least one additional element of the dielectric ceramic composition with respect to 100 parts by mol B-site elements, and β (unit: parts by mol) denotes a content of the at least one additional element of the grain boundary with respect to 100 parts by mol B-site elements.

The present invention belongs to the field of microwave dielectric ceramic materials, and specifically provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect, so that the prepared zinc-magnesium-titanium microwave dielectric ceramic material has low dielectric loss and low resonant frequency temperature coefficient, and is suitable for manufacturing ceramic substrates with excellent performance. 0.7 Mg 0.3 TiO3 system, by introducing Mn element, makes the material produce Jan-Taylor effect, distorts the crystal structure, hinders ion migration, and enhances the structural stability of the ceramic; finally, the present invention improves the Zn 0.7 Mg 0.3 The dielectric properties of TiO3 microwave ceramics have obtained a microwave dielectric ceramic material with a dielectric constant of 20.689, Q×f=50807.9, and a resonant frequency temperature stability coefficient of ‑22.3ppm / ℃, which is expected to be used in the manufacture of ceramic substrates.

The invention discloses a colossal dielectric zinc oxide ceramic as well as a preparation method and application thereof, and belongs to the technical field of functional dielectric ceramics and preparation thereof. The problems that an existing ZnO ceramic material is low in dielectric constant, large in dielectric loss, poor in frequency stability and incapable of having the colossal dielectric property are solved. According to the invention, Li2O and Al2O3 are adopted to carry out composite doping on ZnO, and a discharge plasma sintering mode is combined, so that the dielectric property of the ZnO ceramic is designed, and the colossal dielectric property is obtained. By adopting a discharge plasma sintering mode, the sintering temperature and time are reduced, the generation of intrinsic defects is inhibited, and the dielectric loss is reduced; li2O and Al2O3 are adopted for composite doping, intrinsic defects are restrained, meanwhile, segregation of doped ions at the grain boundary is utilized to form a grain boundary capacitance barrier, the dielectric constant of the doped ceramic is increased, and the prepared zinc oxide-based ceramic has the colossal dielectric property and is good in frequency stability.

The present disclosure provides a dielectric paste composition, a dielectric ceramic sheet, and a method of manufacturing a multilayer electronic component. The dielectric slurry composition comprises dielectric particles, a solvent, a dispersant and an adhesive, the dielectric particles comprise BaTiO3, the solvent comprises ethanol and toluene, the dispersant comprises polyvinylpyrrolidone, and the mass ratio of the ethanol to the toluene is greater than 1.0 and less than 2.3.

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.

The invention discloses a sintering furnace for preparing low-dielectric ceramic, and relates to the technical field of ceramic preparation. The sintering furnace comprises a sintering furnace body, a separation cage, a rotary switching mechanism and a collection box, the sintering furnace body comprises an outer furnace body and an inner furnace body, and the inner furnace body is fixedly installed in the outer furnace body. The separation cage is pushed into the inner furnace body, so that the low-dielectric ceramic is located in a cage cover of the separation cage, and in the glue discharging stage of low-dielectric ceramic sintering, the separation rotating plates are rotated, so that the separation rotating plates in the outer ring are converted into the mutually-attached sealing state from the interval state pointing to the axis, and the low-dielectric ceramic sintering is achieved. When gas and solid waste are generated during glue discharging of the low-dielectric ceramics, solid dust and particles fall onto the surfaces of the partition rotating plates which are tightly arranged, the gas drives powder on the partition rotating plates and powder on the low-dielectric ceramics to be discharged out of the furnace, and the situation that the powder falls onto a heating part in the inner furnace body is avoided; and the phenomena of oxidation, corrosion, non-uniform temperature distribution and the like of a heating part are avoided.

To provide a multilayer ceramic electronic component capable of improving bias characteristics while maintaining ferroelectricity.SOLUTION: A multilayer ceramic electronic component includes: a dielectric layer that has barium titanate as a main component, and has a core portion and a shell portion covering the core portion, in which calcium is solid dissolved in the shell portion, and includes a plurality of crystal grains in which a calcium concentration in the shell portion is 10 times or more a calcium concentration in the core portion; an internal electrode that is provided with the dielectric layer interposed therebetween, and has nickel or copper as a main component; and an external electrode that is electrically connected to the internal electrode.SELECTED DRAWING: Figure 1

Provided is a multilayer ceramic capacitor 1 comprising a layered body 10 including a dielectric ceramic layer 20 and internal electrode layers (21, 22) layered in a layering direction T, wherein: the layered body 10 has a substantially rectangular parallelepiped shape having a first main surface 11 and a second main surface 12 that face each other in a layering direction T, a first side surface 13 and a second side surface 14 that face each other in a width direction W orthogonal to the layering direction T, and a first end surface 15 and a second end surface 16 that face each other in a length direction L orthogonal to the layering direction T and the width direction W; a WT cross section that is a cross section of the layered body 10 taken along the width direction W and the layering direction T has Ni non-segregation parts (41, 43) that are present in a region at a prescribed thickness from at least one surface of the layered body 10 toward the interior of the layered body 10, and Ni segregation parts (42, 44) that are present farther into the layered body than the Ni non-segregation parts (41, 43) and contain Ni segregated in the dielectric ceramic layer 20; and a boundary (d) between the Ni non-segregation parts (41, 43) and the Ni segregation parts (42, 44) is positioned in a region of 5-20 μm from the surface of the layered body 10 toward the interior of the layered body 10.

The present disclosure relates to a low dielectric constant borate microwave dielectric ceramic and a preparation method thereof. The main raw materials of the low dielectric constant borate microwave dielectric ceramic are B2O3, SnO2 and SrCO3, and the chemical composition expression is SrSn(BO3)2. The preparation process of the low dielectric constant borate microwave dielectric ceramic provided by the embodiment of the present disclosure is simple, and the powder synthesized by the high temperature solid phase reaction method has a high purity. Compared with the existing microwave dielectric ceramic materials, the prepared low dielectric constant borate microwave dielectric ceramic has excellent performance, a lower dielectric constant, and a higher quality factor. The dielectric constant is 5.42 to 6.12, the temperature coefficient is ‑48.31ppm / °C to ‑53.37ppm / °C, and the quality factor is 22142GHz to 32618GHz.

A multilayer ceramic capacitor includes dielectric ceramic layers and inner electrode layers. The dielectric ceramic layers include crystal grains including a perovskite oxide including at least one A-site element and at least one B-site element. When a cross-section of the dielectric ceramic layers is observed using a scanning transmission electron microscope, the dielectric ceramic layers include grains, on which a plane of a perovskite structure is observed, as crystal grains. The grains, when subjected to compositional analysis by energy dispersive x-ray spectroscopy, have an atom-distributed region in which a concentration of the A-site element or B-site element (c) subtracted from a maximum concentration of the element (cmax) (Δc=cmax−c) is about 2 atm % or less, at one or more atomic sites in the grains, and an area of the atom-distributed region (SΔc≤2%) is about 0.050 nm2 or less.