16 results about "Microwave dielectric properties" patented technology

The application discloses a kind of multi-element mineral microwave dielectric ceramic materials and preparation method thereof, multi-element mineral microwave dielectric ceramic materials, by the following weight fraction raw materials sintering is obtained: 192~224 parts black talc, 160~192 parts wollastonite, 8~12 parts MgO, 4~8 parts SnO2, 2~4 parts kaolin tailings.Preparation method includes the following steps: broken fine sieving, obtain black talc powder, wollastonite powder and kaolin tailings powder;Take black talc powder and MgO powder, ball milling is mixed;Add wollastonite powder, continue ball milling;Drying, calcination, heat preservation, with furnace cooling;The obtained powder and proportionally weighed SnO2 powder, kaolin tailings powder, ball milling is uniformly mixed, drying;After powder preparation blank, sintering.The application improves the microwave dielectric properties of ceramic material, selects kaolin tailings powder as sintering additive, reduces sintering temperature under the premise of not reducing ceramic dielectric properties.

The application relates to the field of electronic information functional ceramics and electronic devices, and discloses a kind of ultra-low dielectric constant microwave dielectric ceramic and preparation method thereof, the composition expression of the ultra-low dielectric constant microwave dielectric ceramic is: xMg2SiO4-(1-x)LiAl 0.925 B 0.075 O2+ywt.%MO, MO is sintering aid, wherein: 0.2<=x<=0.4, 0.5<=y<=1, the sintering temperature of the ultra-low dielectric constant microwave dielectric ceramic is 1000~1100 DEG C, the dielectric constant of the microwave dielectric ceramic prepared by the application can reach 4.9~5.8, Qxf value can reach 51539~60754 GHz, frequency temperature coefficient Tf can reach-16.2~-11.3ppm / DEG C, the ultra-low dielectric constant microwave dielectric ceramic can be prepared at lower sintering temperature, meanwhile Qxf value is high, better microwave dielectric performance can be obtained, and the resonant frequency temperature coefficient is low, and temperature stability is good.

The application discloses a preparation method of low-dielectric-loss high Q × f value lithium titanate-based microwave dielectric ceramic material and a product thereof.The application takes Li2CO3, TiO2, Sc2O3 and Nb2O5 as raw materials, substitutes Ti in Li2TiO3 with (Sc 1 / 2Nb 1 / 2 ) 4+ , forms a lithium titanate-based microwave dielectric ceramic material with a chemical formula of Li2Ti 4+ (Sc 1‑x Nb 1 / 2 ) 1 / 2 x O3, effectively adjusts the phase structure of the microwave dielectric ceramic, optimizes the temperature frequency characteristics and dielectric loss, and obtains excellent comprehensive microwave dielectric performance with moderate dielectric constant, super high Q × f value and near-zero resonance frequency temperature coefficient, so that the lithium titanate-based microwave dielectric ceramic material has great application potential in the fields of next-generation mobile communication and satellite communication.

The invention discloses a low-temperature sintering temperature-stable oxyfluoride nanocrystalline ceramic and a preparation method thereof, the chemical formula of the nanocrystalline ceramic is Li3Mg2SbO5. 8F0.4, the crystal structure of the nanocrystalline ceramic is composed of an orthorhombic-phase primary crystal phase and a cubic-phase secondary crystal phase, and the average grain size is 220-240 nm. A proper amount of MgF2 is introduced into Li3Mg2SbO6 to serve as a magnesium source, so that the Li3Mg2SbO6-based ceramic crystal structure and the grain size are changed, and meanwhile, the Li3Mg2SbO6-based ceramic has low-temperature sintering (1t, 900 DEG C) and good microwave dielectric properties: tau f is-13.1 to-9.5 ppm / DEG C, Q * f is 33300 to 56600 GHz, and epsilon r is 9.8 to 10.4. The ceramic material is simple in preparation process, rich in raw materials, low in cost and beneficial to industrial production, and can be widely applied to manufacturing of low-temperature co-fired ceramic systems, dielectric resonators, dielectric antennas and other electronic components.

This invention relates to the field of dielectric ceramics technology, specifically to a low-dielectric-high-entropy microwave dielectric ceramic with a garnet structure and its preparation method. The chemical composition formula of the low-dielectric-high-entropy microwave dielectric ceramic with a garnet structure is Ca. 3 (Co 0.2 Cu 0.2 Mg 0.2 Zn 0.2 Ni 0.2 ) 2 SiV 2 O 12 By introducing the high-entropy effect into the garnet structure and optimizing the sintering temperature, a Ca with a garnet structure was successfully synthesized. 3 (Co 0.2 Cu 0.2 Mg 0.2 Zn 0.2 Ni 0.2 ) 2 SiV 2 O 12 Pure-phase low-dielectric-high-entropy microwave dielectric ceramics. They exhibit a dielectric constant of 6.5–10.4, a quality factor of 12490–62440 GHz, and a temperature coefficient of resonant frequency of -9.2–-7.4 ppm / ℃. These ceramics possess excellent microwave dielectric properties and have significant practical application value.

The invention discloses a preparation method of Li3Mg2SbO6 ceramic with improved sintering characteristic and microwave dielectric property, which comprises the following steps: weighing Li2CO3, MgO and Sb2O5 according to the stoichiometric ratio of the general chemical formula Li3Mg2SbO6, mixing, ball-milling until the materials are uniformly mixed, drying and sieving to obtain a primary ball-milled material; the primary ball-milled material is placed in a box-type furnace for high-temperature presintering, the presintering temperature is 800-1000 DEG C, the presintering time is 2-6 hours, and secondary ball-milled material is obtained after ball milling, drying and sieving are conducted again; performing cold isostatic pressing on the secondary ball-milled material to obtain a ceramic green body; the ceramic green body is placed in a box-type furnace for high-temperature sintering, the sintering temperature ranges from 1350 DEG C to 1500 DEG C, the sintering time ranges from 2 hours to 6 hours, and the Li3Mg2SbO6 microwave dielectric ceramic is obtained. The preparation process is simple, the sintering characteristic of the ceramic is improved, the obtained microwave dielectric ceramic is a pure phase, the density is relatively high, and the commercialization of Li3Mg2SbO6 ceramic is favorably realized.

The invention discloses an Mg3TiO5 microwave dielectric material and a preparation method thereof, and belongs to the field of microwave dielectric materials, the chemical formula of the microwave dielectric material is Mg3TiO5, the Q * f of the microwave dielectric material is 198000GHz, and the fluctuation of the microwave dielectric property within the range of-50 DEG C to 200 DEG C is less than or equal to 5%; the preparation method comprises the following steps: (1) proportioning MgO or basic magnesium carbonate with the purity of more than 99% and the particle size of 400-600nm and TiO2 according to product element composition to obtain initial powder; (2) carrying out ball milling, drying, sieving and presintering on the initial powder obtained in the step (1), and then carrying out secondary ball milling, drying and sieving; and (3) adding a polyvinyl alcohol solution into the powder obtained in the step (2) for granulation, then carrying out compression molding, and sintering the obtained green body in the air atmosphere of 1320-1440 DEG C to obtain the Mg3TiO5 microwave dielectric material.

The application discloses a non-metallic mineral matter cordierite type microwave dielectric ceramic material, which is sintered from the following raw materials: black talc powder, coal-based kaolin ore powder, bauxite powder and Sm-Mn composite sintering additives, wherein the Sm-Mn composite sintering additives are prepared by pre-sintering Sm2O3 and Mn(NO3)2.4H2O, and the mass percentage of each raw material in the total amount of black talc powder, coal-based kaolin ore powder, bauxite powder, Sm2O3 and Mn(NO3)2.4H2O is as follows: the black talc powder accounts for 46-49%, the coal-based kaolin ore powder accounts for 15-19%, the bauxite powder accounts for 27-31%, the Sm2O3 accounts for 0.5-1.5%, and the Mn(NO3)2.4H2O accounts for 4.5-5.5%, and the main phase of the non-metallic mineral matter cordierite type microwave dielectric ceramic material is cordierite Mg2Al4Si5O 18 12, the secondary phase is SmMn2O5 and MnO2. The application further discloses a preparation method, wherein the Sm-Mn composite sintering additives are sintered first, and then mixed with the mineral raw materials in proportion to prepare by a solid phase sintering method. The non-metallic mineral matter microwave dielectric ceramic material prepared by the application solves the problem of microwave dielectric performance deterioration caused by impurities in the mineral raw materials.

The present application relates to a kind of low dielectric loss and low temperature coefficient microwave dielectric ceramic and its preparation method, the preparation method includes the following steps: after mixing zinc lanthanum titanate, strontium source and auxiliary raw material, sequentially forming and sintering, the low dielectric loss and low temperature coefficient microwave dielectric ceramic is prepared;The auxiliary raw material includes any one or combination of at least two of calcium carbonate, manganese dioxide or barium carbonate.The present application selects zinc lanthanum titanate and strontium titanate with good microwave dielectric properties as basic raw material to ensure the basic performance of ceramic;Introduce appropriate amount of calcium carbonate, manganese dioxide and barium carbonate, effectively reduce the dielectric loss of ceramic, and improve its temperature characteristics;The present application reduces production cost and technical difficulty by solid phase reaction method, while ensuring the uniformity and stability of ceramic, effectively reduces the dielectric loss of microwave dielectric ceramic, and improves its temperature characteristics, further improves the performance of ceramic.

The application relates to the field of electronic information functional ceramics and electronic devices, and discloses a low-temperature sintering microwave dielectric material and a preparation method thereof. 0.98 (Li 2 / 3 Sn 1 / 3 ) 0.02 ]3TiO6‑(1‑x)Ca 0.8 Sm 0.4 / 3 TiO3+ywt.%MO, the MO being a sintering aid, wherein 0.1<=x<=0.5 and 0.4<=y<=1; the microwave dielectric material prepared by the application has excellent microwave dielectric properties: the dielectric constant can reach 40-55, the Qxf value can reach 45000-60000 GHz, and the frequency temperature coefficient tauf can reach 0.8-4.9 ppm / degree Celsius.

Providing a dielectric ceramic composition, a method for making the dielectric ceramic composition and related devices. The dielectric ceramic composition includes the following elements: Mg, Ca, Si, Ti, and O. When the dielectric ceramic composition is expressed in terms of oxide form, molar amounts satisfy: 50 mol%≤ MgO ≤ 65 mol%, 3 mol%≤ CaO ≤ 6 mol%, 22 mol%≤ SiO 2≤ 35 mol%, 0.5 mol%≤ La 2O 3 ≤ 1.5 mol%, and 4 mol%≤ TiO 2 ≤ 14 mol%, where MgO+ CaO+ SiO 2 +La 2O 3 + TiO 2 = 100 mol%. The dielectric ceramic composition shows a good combination of microwave dielectric properties.

The invention discloses a low-temperature sintered microwave dielectric ceramic and a preparation method thereof, and the preparation method comprises the following steps: pre-sintered ceramic powder is subjected to wet sanding until the particle size D50 is 0.60-0.68 [mu] m to obtain ceramic slurry; under the condition of high-speed stirring, adding an acid solution into the ceramic slurry, and adjusting the pH value of the system to 9-10; sequentially adding an organic additive system containing a binder, a plasticizer, a dispersant, a lubricant, a defoaming agent and a surface modifier into the ceramic slurry; the obtained mixed slurry is sequentially subjected to drying, granulation, sieving, compression molding, glue discharging and sintering, and the microwave dielectric ceramic is obtained. By optimizing the powder pretreatment and organic additive introduction process, the method realizes full densification sintering of the ceramic at a low temperature of 1150-1250 DEG C, and successfully prepares the microwave dielectric ceramic with high density, excellent microwave dielectric properties and good surface quality.

The application discloses a perovskite-based low-temperature co-fired ceramic and a preparation method and application thereof. The low-temperature co-fired ceramic is composed of lithium-boron-silicon glass and CaTiO3, and the mass ratio of the lithium-boron-silicon glass to the CaTiO3 is (10-30):(90-70). The lithium-boron-silicon glass with a low softening point and a small high-temperature viscosity is obtained by selecting each component and controlling the proportion of each component, so as to reduce the sintering temperature of the perovskite, greatly reduce the required glass content for densifying the low-temperature co-fired ceramic, and improve the microwave dielectric properties of the low-temperature co-fired ceramic. Then, the dielectric constant of the low-temperature co-fired ceramic is regulated by controlling the composition and proportion of the low-temperature co-fired ceramic and the particle size of the ceramic. Compared with the current mainstream LTCC medium material, the dielectric constant of the perovskite-based low-temperature co-fired ceramic is higher, is 85-110, and simultaneously meets the low-temperature sintering requirement of the LTCC technology, so that the matching property of the low-temperature co-fired ceramic and a substrate material is better, and the actual application requirement is met.

This invention discloses a tungsten bronze-structured barium lanthanum titanium-based high-entropy microwave dielectric ceramic and its preparation method, belonging to the field of microwave dielectric ceramics. The chemical formula of the microwave dielectric ceramic is Ba4(La). 1 / 5Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 Eu 1 / 5 ) 28 / 3 Ti 18 O 54 Its preparation method includes: mixing raw materials BaCO3, La2O3, and Pr6O 11 Nd₂O₃, Sm₂O₃, Eu₂O₃, and TiO₂ were formulated according to their chemical formulas, ball-milled, dried, and pre-fired at 1100–1200℃. After a second ball milling, drying, granulation, and sieving, the mixture was pressed into a green body and sintered at 1350–1500℃ to obtain a tungsten bronze structure barium lanthanum titanium-based high-entropy microwave dielectric ceramic. This invention introduces the concept of high entropy into tungsten bronze structure barium lanthanum titanium-based microwave dielectric ceramics for the first time. By controlling process parameters such as pre-firing temperature, sintering temperature, and sintering time, a high-entropy microwave dielectric ceramic with a single-phase tungsten bronze structure was successfully prepared. The high-entropy ceramic prepared by this invention exhibits excellent microwave dielectric properties, including a high dielectric constant, a high quality factor, and a low temperature coefficient of resonant frequency, and is expected to be widely used in the field of mobile communications.

The invention relates to the technical field of inorganic non-metallic materials, in particular to a Li3Mg2NbO6-based low-dielectric-loss microwave dielectric ceramic material and a preparation method of the Li3Mg2NbO6-based low-dielectric-loss microwave dielectric ceramic material. According to the invention, Li3Mg2NbO6 is used as a matrix, Nb < 5 + > is partially replaced by V < 5 + >, Mg < 2 + > is partially replaced by Ni < 2 + >, the Li3Mg2NbO6-based low-dielectric-loss microwave dielectric ceramic material is prepared, the chemical expression is Li3Mg2-xNixNb < 1-y > VyO6, x = y, and 0 lt; and x is less than or equal to 0.04. Through synergistic doping of Ni < 2 + > and V < 5 + >, the sintering temperature is remarkably reduced under the condition that the original microwave dielectric property is stable, and the problem of parameter balance among the dielectric constant, the quality factor and the temperature coefficient of resonance frequency in performance optimization of the low-dielectric-loss microwave dielectric ceramic is solved; and the problem that the dielectric property is unstable due to the fact that impurities are possibly introduced into the added sintering aid is solved.

The invention discloses a Ca2V2O7-based microwave dielectric ceramic and a preparation method thereof, and belongs to the technical field of electronic ceramics. Ni < 2 + > is used for carrying out doping modification on the A site of a Ca2V2O7 group, and the sintering characteristic and dielectric loss of the Ca2V2O7-based microwave dielectric ceramic are synchronously optimized from the crystal structure and phase composition level; through precise ion substitution, the effective reduction of the ceramic sintering temperature and the significant improvement of the quality factor are realized, so that the Ca2V2O7-based microwave dielectric ceramic with low loss and low-temperature sintering characteristics is obtained. According to the invention, no external sintering aid is added, the regulation of sintering dynamics and microstructure is realized by completely depending on the regulation of Ni < 2 + > on the crystal structure and phase composition of the Ca2V2O7 ceramic, and the negative effects of impurity phase and amorphous interface caused by the introduction of glass phase or low-melting-point compound are avoided; the stability of the microwave dielectric property of the Ca2V2O7-based microwave dielectric ceramic is ensured, and the reliability of the microwave dielectric ceramic is improved.