274 results about "Ferroelectricity" patented technology

There is provided a method of forming a thin film of vinylidene fluoride homopolymer having crystal form I which is applicable to various substrates in relatively easy way (coating conditions, application method, etc.), a process for preparing a vinylidene fluoride homopolymer having crystal form I efficiently at high purity, and novel vinylidene fluoride homopolymers which can give a thin film being excellent in ferroelectricity. The method of forming a thin film of vinylidene fluoride homopolymer comprises (i) a step for preparing a green powder product of vinylidene fluoride homopolymer comprising crystal form I alone or as main component by subjecting vinylidene fluoride to radical polymerization in the presence of a bromine compound or iodine compound having 1 to 20 carbon atoms which contains at least one moiety represented by —CRf¹Rf²X¹, wherein X¹ is iodine atom or bromine atom; Rf¹ and Rf² are the same or different and each is selected from fluorine atom or perfluoroalkyl groups having 1 to 5 carbon atoms and (ii) a step for forming a thin film on a substrate surface by using vinylidene fluoride homopolymer which comprises crystal form I alone or as main component and is obtained from the green powder product of vinylidene fluoride homopolymer comprising crystal form I alone or as main component.

The invention relates to a blue-excited red fluorescent material and a preparation method thereof, belonging to the field of luminescent materials. The blue-excited red fluorescent material has the following chemical expression: Ca1+d-x-mAmRxBi2Ta2-nBnO9:fC, wherein the R is selected from one or more rare earth elements of Pr, Sm, Eu and Lu; the A is selected from one or more than one of Sr, Ba, Mg, Zn and Cu; the B is selected from one or two of Nb and V; the S is selected from one or more than one of Li, Na, K, Ti, Ag, B, Al, Ga and In, the x is not less than 0.00001 and is not more than 0.1; the m is not less than 0 and is more than 0.99; the n is not less than 0 and is not more than 1.99; the d is not less than 0 and is not more than 0.1; and the f is not less than 0 and is not more than 0.1. The blue-excited red fluorescent material not only has the properties of piezoelectricity, ferroelectricity and dielectricity, but also has the characteristic of blue-excited red emission, belongs to a photoelectric multifunctional material and can be widely applied to the fields of white light LED (Light Emitting Diode), optoelectronic integration, micro electromechanics, photoelectric sense, and the like.

Provided are a ferroelectric material having good ferroelectricity and good insulation property, and a ferroelectric device using the ferroelectric material. In the present invention, the ferroelectric material includes a metal oxide having a perovskite-type crystal structure, in which: the metal oxide contains bismuth ferrite whose iron is substituted by manganese, and at least one of a copper oxide and a nickel oxide; the bismuth ferrite is substituted by manganese at a substitution ratio of 0.5 at. % or more to 20 at. % or less with respect to a total amount of iron and manganese; and at least one of the copper oxide and the nickel oxide is added in an amount of 0.5 mol % or more to 20 mol % or less with respect to the bismuth ferrite whose iron is substituted by manganese.

A ferroelectric layer having a low dielectric constant which is used for a ferroelectric memory element is provided. Also, the ferroelectric layer having a high melting point used for the ferroelectric memory element is provided. An FET 20 has a stacked structure including a gate oxidation layer 24, a floating gate 26, a ferroelectric layer 28, and a control gate 30 deposited on a channel region CH in that order, the channel region CH being formed in a semiconductor substrate 22 made of silicon. The ferroelectric layer 28 consists of a thin film made of a mixed crystal composed of Sr2(Ta1-xNbx)2O7. The crystal structure of both Sr2Nb2O7 and Sr2Ta2O7 is pyramid quadratic structure, and their lattice constants are similar to each other. Their relative dielectric constants are low, and their melting points are high. Curie temperature related with their ferroelectricity is, however, too high in Sr2Nb2O7 and too low in Sr2Ta2O7. In order to overcome the discrepancies, the ferroelectric layer 28 having desired curie temperature is formed with a mixed crystal made of Sr2(Ta1-xNbx)2O7.

Provided are an oxynitride piezoelectric material which exhibits ferroelectricity and has good piezoelectric properties and a method of producing the oxynitride piezoelectric material. The oxynitride piezoelectric material includes a tetragonal perovskite-type oxynitride represented by the following general formula (1):

A_1-xBi_x+δ1B_1-yB′_y+δ2O_3-zN_z  (1)

where A represents a divalent element, B and B′ each represent a tetravalent element, x represents a numerical value of 0.35 or more to 0.6 or less, y represents a numerical value of 0.35 or more to 0.6 or less, z represents a numerical value of 0.35 or more to 0.6 or less, and δ1 and δ2 each represent a numerical value of −0.2 or more to 0.2 or less, in which the A includes at least one kind selected from Ba, Sr, and Ca and the B and the B′ each include at least one kind selected from Ti, Zr, Hf, Si, Ge, and Sn.

The invention relates to a piezoelectric ceramic fiber containing a metal core. The invention includes a metal core (1), a piezoelectric ceramic material (2) which coats the metal core (1) and a coating electrode (3) which is coated on the outer surface of the piezoelectric ceramic material (2); the value of the diameter (d) of the metal core (1) is more than or equal to 10 microns and is less than or equal to 200 microns; the metal core (1) is composed of metal materials which are high temperature resistant of 1000 DEG C to 3500 DEG C and are not easy to be oxidized; the piezoelectric ceramic material (2) is the piezoelectric ceramic material with a perovskite structure; the ceramic part and the metal core part of the piezoelectric ceramic fiber containing a metal core of the invention have good combination; wherein, the metal core can be used as an electrode, therefore, only the outer surface of the piezoelectric ceramic fiber needs to be plated with the electrode, and the single fiber can be used as a sensor or a driver; the invention has typical ferroelectricity and typical strain-electric field relation curve of the piezoelectric material, thus the invention can be taken as a driving element.

A ferroelectric device and a manufacturing method are provided. While holding a nonvolatile memory retention capability and a multiple rewriting endurance as the distinctive features of a ferroelectric device, the disclosed ferroelectric device is wider in memory window and more adaptively made microfiner than a conventional ferroelectric device that has used a ferroelectric mainly constituted of Sr—Bi—Ta—O as an oxide of strontium, bismuth and tantalum. Directly on or with intermediary of an insulator on a semiconductor there are layered a first ferroelectric and a conductor to form a gate stack, the first ferroelectric being mainly constituted of Sr—Ca—Bi—Ta—O as an oxide of strontium, calcium, bismuth and tantalum and being built up by a metal organic vapor deposition technique from a suitable film-forming raw material. The gate stack is heat-treated to cause the first ferroelectric to develop its ferroelectricity.

The invention discloses a force-electricity coupling dynamic fracture experimental system in the technical field of mechanical structural deformation and mechanical experiments. The force-electricity coupling dynamic fracture experimental system is used for realizing experimental studies on fracture characteristics of piezoelectric and ferroelectric materials under a dynamic force-electricity coupling load field. The system comprises a dynamic mechanical load loading unit, a dynamic pulse electric load loading unit, an insulation supporting protection unit, a dynamic control unit, a data collection unit and a data processing unit. The dynamic mechanical load loading unit is connected with the insulation supporting protection unit which is connected with an experimental specimen which is connected with the dynamic pulse electric load loading unit, and the dynamic control unit is respectively connected with the dynamic mechanical load loading unit, the dynamic pulse electric load loading unit and the data collection unit which connected with the data processing unit. The force-electricity coupling dynamic fracture experimental system provides an effective guarantee for dynamic fracture performance tests of piezoelectricity and ferroelectricity.

The present invention relates to a glass matrix which includes 4-70 wt.% SiO2, 0.5-20 wt.% Al2O3, 0-20 wt.% R2O, 0-30 wt.% R'O, 8-85 wt.% Ta2O5, 0-40 wt.% Nb2O5, and 0.01-1.0 wt.% R''2O3, where R2O + R'O is between about 2-35 wt.%, Ta2O5 + Nb2O5 is between about 8-85 wt.%, R is selected from a group consisting of Li, Na, K, and combinations thereof, R' is selected from a group consisting of Ba, Sr, Ca, Mg, Zn, Pb, and combinations thereof, and R'' is a rare earth element. The present invention also relates to use of the glass matrix in forming optic waveguides such as optic amplifiers. The present invention further relates to a transparent glass ceramic that contains pyrochlore, perovskite, or a combination thereof as its major crystal phase, and includes 4-40 wt.% SiO2, 1-15 wt.% Al2O3, 0-20 wt.% K2O, 0-12 wt.% Na2O, 0-5 wt.% Li2O, 8-85 wt.% Ta2O5, and 0-45 wt.% Nb2O5, wherein Ta2O5 + Nb2O5 is at least about 20 wt.% and (K2O + Li2O + Na2O) is between about 5-20 wt.%. Also disclosed is a method of making the glass ceramic and use of the glass ceramic as a ferro-electric component in electro-optical devices or as a filtering core in an optical filtering device.

The invention discloses a laminated single-phase multi-ferric material. The general formula of the material is ABM2O5, wherein A is one or more of Na, K, Rb and Cs; B is one or more of Bi and Pb; and M is one or more of Mn, Fe, Co, Ni and Cu. The invention further provides a hydrothermal preparation method and a high-temperature solid-phase preparation method of the multi-ferric material. The material is a newfound laminated structural material with a non-perovskite structure. In the structure of the material, G-type antiferromagnetic spin alignment is formed under the interaction of tetra-coordinated M ions, so that spinning inclination is facilitated to generate a net magnetic moment; and 6s2 lone pair electrons of A (Bi<3+> and Pb<2+>) ions are a source which keeps a sample be in a ferroelectric state. The multi-ferric material has wide application prospects in the aspects of information storage, spinning devices and sensors.

The invention provides a ferromagnetism / ferroelectricity composite material which comprises ferrite YA1IG-16A and modified bismuth ferrite BLFTO, and the molecular formula of the modified bismuth ferrite BLFTO is (Bi0.87La0.13) (Fe0.92Ti0.08) O3, wherein the volume ratio of the YA1IG-16A and the modified bismuth ferrite BLFTO is 1:(0.8-1.2). The invention further provides a preparation method of the ferromagnetism/ferroelectricity composite material and a C-waveband miniaturized microwave isolator manufactured through the ferromagnetism / ferroelectricity composite material. The ferromagnetism / ferroelectricity composite material can be used for aerospace, microwave communication and radar receiver systems. The bottleneck of miniaturization of microwave isolators is broken through, the novel ferromagnetism / ferroelectricity composite material has high dielectric constant, the miniaturization problem of microwave isolators can be fundamentally solved, and the ferromagnetism / ferroelectricity composite material is the key technology of miniaturization of microwave isolators.

The invention provides an electric field write-in and resistance readout solid-state storer component, a storer and a read-write method of the storer. The invention relates to a novel nonvolatile solid-state storage component, a storer, and a corresponding write-in and readout method. The solid-state storage component comprises a bottom electrode layer, a ferroelectricity piezoelectric layer formed on the bottom electrode layer, a resistive layer which is close to the ferroelectricity piezoelectric layer and placed on the ferroelectricity piezoelectric layer, and a top electrode layer which is placed on the resistive layer, wherein the ferroelectricity piezoelectric layer is used as an information storage layer and has two or more straining states under the effect of the electric field, and the resistive layer has two or more nonvolatile resistance states, so that the resistive layer can be used as the information readout layer. According to the solid-state storage component, the information is written in through the electric field and can be read out in a non-destructive manner; and the solid-stage storage component has the advantages of being low in power consumption, nonvolatile, fast in storage speed, and high in storage density.

The invention relates to a dysprosium-doped BiFeO3 multi-ferroic ceramic block and a preparation method thereof and belongs to the field of functional ceramic. The preparation method comprises the following steps: weighting Bi(NO3)3.5H2O, Dy2O3 and Fe(NO3)3.9H2O at a ratio of (1-x):x:1; respectively dissolving in glacial acetic acid, diluted nitric acid and water, heating and stirring; mixing thethree solutions, and then adding citric acid, heating and stirring; after adjusting PH, continuously heating and stirring, thereby obtaining gel; foaming the gel, thereby obtaining aerogel; crushing the aerogel, thereby obtaining powder; pre-processing the powder; making the pre-processed powder into block and sintering; and removing a surface oxide layer, thereby obtaining the B(i1-x)DyxFeO3 multi-ferroic ceramic block, wherein x is equal to 0.03-0.20. The Bi(1-x)DyxFeO3 multi-ferroic ceramic block is single-phase ceramic; the ferroelectricity is enhanced; and when x is equal to 0.05 and 0.07, the ceramic block has ferromagnetism at room temperature.

The invention provides a Bi0.9Er0.1Fe1-xCoxO3 film with high ferromagnetism and ferroelectricity, and a making method thereof. The method comprises the following steps: preparing a Bi0.9Er0.1Fe1-xCoxO3 precursor solution from bismuth nitrate, iron nitrate, cobalt nitrate and erbium nitrate, spin-coating a substrate with the Bi0.9Er0.1Fe1-xCoxO3 (x is 0.01-0.03) precursor solution, uniformly sizing, drying, and annealing to obtain the Bi0.9Er0.1Fe1-xCoxO3 film with high ferromagnetism and ferroelectricity. The method has the advantages of simple device requirements, easy reaching of experiment conditions, easy control of the doping amount, and great improvement of the ferromagnetism of a BiFeO3 film, and the Bi0.9Er0.1Fe1-xCoxO3 film made in the invention has the advantages of good uniformity, high magnetic intensity and high remanent polarization.

The invention discloses a multiferroic liquid and a preparation method thereof, for solving the defects that a solid-state multiferroic material is large in coercive force, cannot be structurally changed once being formed, is low in magneto-electric coupling effect and is easily broken down by voltages. The multiferroic liquid is internally provided with a magnetic material, the outer surface of the magnetic material is wrapped by a ferroelectric material, nanometer particles with magneto-electric core shell structures are uniformly dispersed in a mixed liquid of a base solution and a surfactant, and a stable suspending liquid is formed in such a way. The multiferroic liquid has ferroelectricity and magnetism, also has fluidity and is quite small in coercive force. The length and the thickness of a nanometer chain composed of the nanometer particles in the multiferroic liquid can be adjsuted by applying different electric fields or magnetic fields to the multiferroic liquid according to needs, and accordingly, the electrical property, the magnetic property, the hydrodynamic property, the optical property and the acoustic property of the multiferroic liquid are adjusted. The invention brings forward the concept of the multiferroic liquid for the first time ever, and also provides the preparation method, expanding a new research direction for research on a multiferroic material.

The invention discloses a potassium-sodium lithium niobate-base lead-free piezoelectric ceramic complex with good temperature stability, a preparation method and application thereof. The general formula of the complex is as follows: (1-x) (K0.5Na0.5)0.94Li0.06NbO3-xY, wherein, x is equal to 0-0.05 and Y is a perovskite structural component. The complex has the characteristics of good ferroelectricity, relatively higher remanent polarization, relatively higher piezoelectric property, high Curie temperature, low room-temperature dieiectric loss and good temperature stability, thus being applicable to devices such as a piezoelectric actuator, an energy converter, a sensor, a buzzer and the like.

The invention discloses a transparent extended p-n heterojunction thin film and a preparation method thereof. The thin film comprises a SrTiO3, a LaxSr1-xSnO3 extended thin film, and any one of the following two extended thin films: a PbZr0.52Ti0.48O3 extended thin film and a BiFeO3 extended thin film, wherein the SrTiO3 is used as a mono-crystal substrate, the LaxSr1-xSnO3 extended thin film is arranged above the mono-crystal substrate and x is not less than 0.03 but is not more than 0.07, and the PbZr0.52Ti0.48O3 extended thin film and the BiFeO3 extended thin film is arranged above the LaxSr1-xSnO3 extended thin film. In the p-n heterojunction thin film provided by the invention, every layer thin film has better mono-crystal extensionality and is of a perovskite structure, the p-n heterojunction thin film not only has better rectification characteristic, but also has high penetration rate within the optical wavelength range of 400-2500 nm (p layer is PZT) and 500-2500 nm (p layer is BFO) of the whole device; the P layer materials (PZT, BFO) are ferroelectric material at the same time, wherein the BFP has both ferroelectricity and antiferromagnetism and has larger potential in the application of semiconductor device.

The invention discloses a coordination polymer with ferroelectric properties and a preparation method and application thereof. The chemical formula of the coordination polymer is Cd(C17H15N2O2)Cl; at a room temperature, a soluble compound containing Cd<2+> and a phenylalanine derivative are fully mixed and stirred in water, and put into a reaction still, so that the coordination polymer is prepared through self-assembly in a hydrothermal method. The coordination polymer can be applied to manufacturing electrooptic devices, information storage devices, non-linear optic devices and infrared sensors. According to the the coordination polymer with the ferroelectric properties disclosed by the invention, the adoptive materials are simple in preparation process, the operation is easy, the raw material resources are rich, the production cost is low, the productivity is high, and the repeatability is good; the coordination polymer is unlikely to dissolve in ordinary solvent, the thermal decomposition temperature point is relatively high, and the crystal particles are uniform.

The invention discloses a preparation method for SLTON perovskite-type NOx powder. The method comprises the following steps: completely resolving a soluble strontium salt, a soluble lanthanum salt, a soluble tantalum salt and a combustion adjuvant in a methanol-water mixed solution, drying the solution, carrying out grinding till the raw materials are completely mixed uniformly, carrying out high-temperature calcination to form a precursor, and conducting nitriding high-temperature processing on the precursor to obtain the target product, wherein the molar ratio of the soluble tantalum salt to the combustion adjuvant is 1 to (1 to 500); the soluble strontium salt is one or the mixture of strontium chloride and strontium nitrate; the soluble lanthanum salt is one or the mixture of lanthanum chloride and lanthanum nitrate; the soluble tantalum salt is one or the mixture of tantalum pentachloride and tantalum ethylate; the combustion adjuvant is one or the mixture of urea, oxalic acid, citric acid and hexamethylenetetramine. The method has the advantages that the product purity is high; the impurity content is low; suitability for batch production and the fields of ferroelectricity, photo-electricity, photocatalysis, fuel cells and the like is realized.