307 results about "Ferroelectric ceramics" patented technology

The invention relates to a capacitive flexible pressure sensor based on a composite material dielectric layer and a preparation method of the capacitive flexible pressure sensor and belongs to the technical field of sensors. The flexible pressure sensor includes an upper flexible substrate and a lower flexible substrate, and an upper conducting layer attached to the inner surface of the upper flexible substrate and a lower conducting layer attached to the inner surface of the lower flexible substrate. The composite material dielectric layer is arranged between the upper conducting layer and the lower conducting layer. Compared with the prior art, doping is performed on dielectric layer polymer resin of the capacitive flexible pressure sensor. The doping material includes metal conductors, ferroelectric ceramics, carbon material and organic semiconductors. By adopting the above doping material, the flexibility of the capacitive flexible pressure sensor is improved effectively and the application and promotion of the sensor are facilitated.

This invention relates to a negative permeability device with adjustable electric field based on ferroelectric ceramic particles and its preparation method, in which, the device is composed of two parallel metal pole plates, multiple laminated teflon templates set between the two pole plates, ferroelectric ceramic particles and DC supply, in which, a hole array is set on each teflon template filled with the particles, and the device can drive electromagnetic waves to generate strong magnetic resonance at a certain band and have isotropical negative permeability effect adjacent to the magnetic resonance to realize controlling negative magnetic conductivity and utilizes the adjustment property of field to dielectric constant of ferroelectric ceramic particles to realize controlling its negative permeability.

An antiferroelectric ceramic material that can be formed into a multilayer capacitor is disclosed. The antiferroelectric ceramic material is selected from the Pb(Sn, Zr, Ti)O3 (PSnZT) composition family.

A capacitor material including a thermosetting resin (e.g., epoxy resin), a high molecular mass flexibilizer (e.g., phenoxy resin), and a quantity of nano-particles of a ferroelectric ceramic material (e.g., barium titanate), the capacitor material not including continuous or semi-continuous fibers (e.g., fiberglass) as part thereof. The material is adapted for being positioned in layer form on a first conductor member and heated to a predetermined temperature whereupon the material will not possess any substantial flaking characteristics. A second conductor member may then be positioned on the material to form a capacitor member, which then may be incorporated within a substrate to form a capacitive substrate. Electrical components may be positioned on the substrate and capacitively coupled to the internal capacitor.

Disclosed is a magnetoelectric effect based magnetoelectric memory element of a ferroelectric/ferromagnetic composite thin film. Ferroelectric and ferromagnetic thin films are deposited on a Pt/Ti/SiO<2>/Si composite substrate in sequence to prepare a laminated structure; the chemical structural formula of the ferroelectric thin film with a piezoelectric effect is 0.5Ba(Zr<0.2>Ti<0.8>) O<3>-0.5(Ba<0.3>Ca<0.7>)TiO<3>(BZT-BCT); the thin film with a magnetostrictive effect is Fe<0.7>Ga<0.3>; the preparation method comprises the steps of preparing the ferroelectric ceramic thin film through radio frequency magnetron sputtering, and preparing the ferromagnetic thin film by direct current magnetron sputtering. The magnetoelectric effect based magnetoelectric memory element has the advantages as follows: the memory element is nonvolatile, capable of keeping the polarized and magnetized states under externally-applied voltage, and low in power consumption; the memory unit has good ferroelectric, piezoelectric and ferromagnetic performances at the room temperature; and the maximum electric field control magnetic resistance effect 6% is obtained when the externally applied bias voltage is 20V.

This invention discloses an anti-ferroelectric ceramic capacitor material and its preparation technology, which applies Sn of positive four valency to replace Zr of positive 4 valency, applies the positive 3 valency La to replace 2 valency Pb in the compound of Pb(Zr, Ti) O3 to form a multi-component solid solution with Pb vacancy. The balanced formula of the charge and the valency is: (Pb1-3 2/2Laz)[(Zri-ysny)1-Tix]O3, in which, x varies between 0.06`0.20, y: 0.2010.40, z varies between 0.02-0.08, or positive 2 valency Sr or Ba is added to replace 2 valency Pb in Pb(zr, Ti) O3, the formula is [(Pb1-wBw)1-3z/2Laz][Zr1-ySny]1-xTix ]O3, B expresses Sr or Ba of 2 valency, w varies between 0.02-0.12. A conventional electronic ceramic preparation method is applied in the method.

The invention relates to a ferroelectric piezoelectric ceramic with the characteristic of low sintering temperature. The compositions are (1-x-y)PbZrO3-xPbTiO3-yBi(Zn1/2Ti1/2)O3 and z weight percent of MnO2, wherein x is equal to between 0.30 and 0.50, y is equal to between 0.05 and 0.25, and z is equal to between 0.0 and 0.5. Oxide materials and the prior solid-state reaction electronic ceramic process are adopted to achieve the aim of sintering a compact piezoelectric ceramic chip at a low temperature between 900 and 1,000 DEG C. The PbZrO3-PbTiO3-Bi(Zn1/2Ti1/2)O3 ferroelectric piezoelectric ceramic is a single phase perovskite structure and has a 'hard' piezoelectric property. Presintering powder of the PbZrO3-PbTiO3-Bi(Zn1/2Ti1/2)O3 ferroelectric ceramic powder as a sintering auxiliary, and an electronic ceramic process of solid phase reaction are adopted so as to achieve the low temperature sintering of the strontium-doped lead zirconate titanate at a temperature of 1,050 DEG C as well as the modification of the piezoelectric property. The ferroelectric piezoelectric ceramic is particularly applicable to the manufactures of functional devices such as emission piezoelectric ceramic devices, low-temperature cofiring multi-layer ceramic piezoelectric drives, transformers, and transducers.

Dielectric elastomer material and a preparation process thereof relate to the dielectric elastomer material and the preparation process thereof, which solves the problems existing in the current dielectric elastomer material of low dielectric constant, low deformation, voltage which is exerted to deform close to the disruptive voltage of material. The dielectric elsastomer material is prepared by plasticizer, catalyst and virgin rubber of silicon rubber in silicon resin BJB TC 5005 and relaxation-type ferro-electricity ceramic material. The preparation process comprises firstly agitating raw materials under constant temperature except relaxation-type ferro-electricity ceramic material, then adding relaxation-type ferro-electricity ceramic material to agitate under constant temperature again, and conducting solidification treatment for prepared substances after poured into patternmaking dies. The dielectric elastomer material of the invention has high dielectric constant, large deformation, and voltage for deformation is far lower than the disruptive voltage of the dielectric elastomer material of the invention. The preparation process of the invention is simple, and is easy to be operated, and technique is easy to control.

The invention discloses La2O3-doped lead zirconate titanate antiferroelectric ceramic. The components and the molar ratio of the components of the ceramic are represented by a formula of Pb1-xLax(Zr0.70Ti0.30)1-x/4O3, wherein x=0.07-0.18. According to the invention, a traditional oxide mixing method is adopted, and sintering is carried out under a normal pressure, such that the antiferroelectric ceramic material is obtained. With the antiferroelectric ceramic provided by the invention, a double hysteresis loop can be displayed under room temperature, the loss is low, and the temperature coefficient is relatively small. The antiferroelectric ceramic is mainly applied in high-density energy-storage capacitors, large-displacement actuators, energy transducers, controllable switches, pyroelectric detectors, and the like.

The invention relates to an anti-ferroelectric ceramic material which is sintered at low temperatures and has high energy storage density and a method for preparing the anti-ferroelectric ceramic material. Chemical components of the anti-ferroelectric ceramic material conform to a chemical general formula of Pb<0.97>La<0.02> (Zr<x>Sn<y>Ti<1-x-y>) O<3>+a*wt.% CuO, wherein the x is larger than or equal to 0.4 and is smaller than or equal to 0.6, the y is larger than or equal to 0.4 and is smaller than or equal to 0.6, the a is larger than or equal to 0.2 and is smaller than or equal to 1, the x and the y are mole numbers, and the a is a mass percent. The anti-ferroelectric ceramic material and the method have the advantages that appropriate sintering additives are chosen, and appropriate Zr/Sn/Ti ratios are adjusted, so that the PLZST anti-ferroelectric energy storage ceramic material sintered at the temperatures of 950-1000 DEG C can be obtained; the anti-ferroelectric ceramic material is high in energy storage density and energy storage efficiency, can be used for manufacturing energy storage multilayer ceramic capacitors and has an excellent application prospect.

The invention relates to a PZT (lead zirconate titanate)-based antiferroelectric ceramic material with low curie point TC and a high bidirectional-adjustable dielectric electric field and a preparation method thereof and belongs to the technical fields of electronic materials and devices. The chemical general formula of the PZT-based antiferroelectric ceramic material with bidirectional adjustability of a dielectric electric field is (Pb[0.99-x-y]BaxLay)(Zr0.51Sn 0.39Ti0.10)O3, wherein x is larger than 0 and less than or equal to 0.20, and y is larger than 0 and less than or equal to 0.06. The PZT-based antiferroelectric ceramic material with dielectric bidirectional adjustability has high dielectric coefficient and low dielectric loss under a certain bias voltage in the vicinity of low curie point TC, and the dielectric coefficient is increased and then decreased along with the increase of the bias voltage; the PZT-based antiferroelectric ceramic material has bidirectional dielectric adjustability, simultaneously has high pyroelectric coefficient and pyroelectric current, and can be widely used in the fields of microelectronics, computers, capacitors, sensors, aerospace technologies and the like.

The invention discloses a dielectric energy-storing anti-ferroelectric ceramic material and a preparation method thereof. The preparation method comprises the following steps: mixing an energy-storing density negative temperature coefficient anti-ferroelectric ceramic material and an energy-storing density positive temperature coefficient anti-ferroelectric ceramic material according to the mass ratio being (30-80):(20-70) to obtain mixed powder; and adding a polyvinyl alcohol solution into the mixed powder and sintering to obtain the dielectric energy-storing anti-ferroelectric ceramic material. The energy-storing material, with energy-storing density stability being more than 85 percent within a wide temperature area range (20 to 150 DEG C), energy-storing efficiency being 85 percent (150 DEG C) and lowest energy-storing density being 2.77 J/cm<3>, is obtained through solid solution of the energy-storing density negative temperature coefficient anti-ferroelectric ceramic material and the energy-storing density positive temperature coefficient anti-ferroelectric ceramic material. The technical problem of low temperature stability in the existing anti-ferroelectric ceramic material is solved, and important value on the actual application of the anti-ferroelectric ceramic material is achieved.

The invention discloses a potassium sodium niobate base lead free transparent ferroelectric ceramic material and a preparation method thereof. The formula of the ceramic material is (1-x)(K<0.5>Na<0.5>)Nb<3-x>Sr(Mg<1/3>Nb<2/3>)O3, and x represent the mole number of Sr(Mg<1/3>Nb<2/3>)O3 and is in a range of 0.02 to 0.08. The preparation method comprises steps of preparing raw materials, pre-burning, ball-milling, granulating, pressing, pressure-free sealed sintering, polishing, and silver ink firing; the ceramic material has the advantages of high light transmission, optical isotropy, strong practicality, and easy production, moreover, the preparation method is simple, the repeatability is good, and the yield is high. The test results show that when x is equal to 0.05, the optical transmission rate of the ceramic material is 60-70% in the near infrared area, at the same time, the ceramic material has good electric properties: the remnant polarization is 4.8 [mu]C/cm2, the coercive field is 7.4 kV/cm, the maximal dielectric constant is 2104, the dielectric loss is less than 0.03, and the piezoelectric constant d33 is 48 pC/N.

The invention provides a preparation method of 3 YSZ nano powder. The preparation method comprises the following steps: mixing zirconium oxide and yttrium oxide, adding deionized water and a dispersing agent to form a slurry, stirring and ball milling the slurry, then carrying out sand grinding and spray drying to prepare the nano 3 YSZ powder, wherein the particle size range is less than or equal to 80 nm; the average particle size is less than 50 nm. The process for preparing the powder by the sand grinding technology is simple and convenient, the period is short and the repeatability is good. The deionized water is used as the grinding medium, the problems of high cost and large environmental pollution in the traditional powder preparation process are well solved, and the preparation method can be widely applied to the preparation of high-temperature solid fuel cells, piezoelectric ceramic, oxygen sensors and ferroelectric ceramic.

The invention discloses a lead-free relaxation antiferroelectric ceramic energy storage material, and a preparation method thereof. The chemical formula is (1-x-y)(Na<0.5>Bi<0.5>)TiO<3-x>(Sr<0.7>Bi<0.2>)TiO<3-y>Me<2>O<3>, wherein Me is used for representing one or two elements selected from La, Sm, and Dy, x and y are used for representing molar fractions, 0.2<=x<=0.7, and 0.01<=y<=0.2. The lead-free relaxation antiferroelectric ceramic energy storage material is relatively in energy storage density, energy storage efficiency, and possesses relaxation characteristics, and the preparation method is simple.

A micro refrigerator of ferroelectric ceramics applies ' double stage - overlap' refrigerating structure and it is prepared adapting relaxation and solid solution of PMNT with high electro biological heat effect under wet preparation method of sol - gel . In said method, new mode of physical-chemical thickness reduction and new detecting means of electro biological heat property are applied.

The invention relates to a ferroelectric ceramic with low-temperature sintering property, utilizes ferroelectric ceramic materials with low-temperature sintering property as sintering additives, employs the conventional solid-phase ceramic process, and realizes the non-pressure low-temperature (100 DEG C) sintering of lead zirconate titanate piezoelectric ceramics for commercial purpose and modification in piezoelectric property. The non-pressure low-temperature sintered piezoelectric ceramic sheet, PbZr1-xTixO3-BiCrO3-BiFeO3-PbTiO3, has a single-phase perovskite structure and exhibits 'hardness' piezoelectric property compared with the piezoelectric ceramic powder for commercial purpose and the ceramic sheet made by the conventional sintering process. The inventive ferroelectric ceramic is particularly suitable for the fabrication of functional devices such as emission piezoelectric ceramic devices, low-temperature cofired multi-layer piezoelectric ceramic drivers, transformers, transducers.

The invention relates to an anti-ferroelectric ceramic material and a preparation method thereof. The chemical general formula of the anti-ferroelectric ceramic material is (Pb<0.91>Ba<x>La<0.06-2x/3>) (Zr<y>Sn<1-y>) O<3>, wherein 0<x<0.09, and 0<y<1. Compared with the prior art, the anti-ferroelectric ceramic material prepared by a traditional electronic ceramic preparation process has the characteristics of high energy storage density, small hysteresis, high energy storage efficiency and excellent charge discharge performance, and is of great significance for the development of pulse power capacitors with high energy storage density and high energy storage efficiency with long cycle charge discharge life.

Polymer-ceramic composite materials for use in the formation of capacitors, which materials exhibit very low changes in temperature coefficient of capacitance (TCC) in response to changes in temperature within the range of from about −55° C. to about 125° C. Specifically, these capacitor materials have a change in TCC ranging from about −5 % to about +5 %, in response to changes in temperature within the desired temperature range. The inventive composite materials comprise a blend of a polymer component and ferroelectric ceramic particles, wherein the polymer component includes at least one epoxy-containing polymer, and at least one polymer having epoxy-reactive groups. The inventive polymer-ceramic composite materials have excellent mechanical properties such as improved peel strength and lack of brittleness, electrical properties such as high dielectric constant, and improved processing characteristics.

The invention relates to a method for preparing a high-dielectric constant composite film of a copper phthalocyanine oligomer/polymer, belonging to the field of high-dielectric constant polymer composite materials. The method comprises the following steps: chemically grafting the copper phthalocyanine oligomer to the polymer; and then, preparing the composite film of the copper phthalocyanine oligomer/polymer by a solution casting method. The polymer is any one of polymers with PVDF (polyvinylidene fluoride) group, polyurethane, epoxy resin, acrylic resin elastomer and poly-(p-chloromethyl styrene); and an active benzyl chloride group is required to be added to a PVDF-based polymer before grafting. The composite film prepared by the method provided by the invention is uniform and compact and has better flexibility; when the content of the copper phthalocyanine oligomer is 15%, the dielectric constant of the composite at room temperature and a frequency of 100Hz is higher than 400; the dielectric loss is lower than 0.24; and the property of the composite film is greatly higher than that of usual ferroelectric ceramic/polymer composite materials.