46 results about "Relaxor ferroelectric" patented technology

The invention provides an anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice film with high energy storage density as well as a preparation method and application thereof. The anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice film with high energy storage density comprises a substrate layer, a bottom electrode layer and a plurality of stacked relaxation ferroelectric layers, wherein the bottom electrode layer and the multiple stacked relaxation ferroelectric layers are sequentially arranged on the substrate layer; each relaxor ferroelectric layer sequentially comprises a first functional layer, a second functional layer and a third functional layer from bottom to top; the first functional layer comprises LaFeO3, the second functional layer comprises BiFeO3, and the third functional layer comprises SrTiO3. The anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice thin film with the high energy storage density has small electric leakage performance and high polarization value, and more excellent energy storage performance is achieved.

The invention belongs to the technical field of functional ceramic materials, and provides a lead-free high-entropy relaxor ferroelectric material and a preparation method thereof.The raw materials of the lead-free high-entropy relaxor ferroelectric material comprise ceramic powder and oxide; the chemical general formula of the ceramic powder is (1-x) (Bi < 0.2 > Na < 0.2 > Ba < 0.2 > Sr < 0.2 > Ca < 0.2 >) TiO < 3-x > La (Mg < 1 / 2 > Zr < 1 / 2 >) O3. The ceramic powder is prepared through a high-entropy strategy, a slender ferroelectric hysteresis loop is obtained at the room temperature, the breakdown field strength of the material is obviously improved, meanwhile, high energy storage density and energy storage efficiency are obtained, the energy storage density reaches 13.5 J cm <-3 >, the energy storage efficiency is 94.6%, and the breakdown electric field reaches up to 750 kV cm <-1 >. According to the material design based on the high-entropy strategy, the relaxation characteristic of the material is remarkably improved, the dielectric loss of the ceramic is effectively reduced, and the practical application potential is shown.

This invention discloses a superparaelectric perovskite ceramic material with A and B site components, its preparation method, and its application. The chemical formula of the superparaelectric perovskite ceramic material with A and B site components is (Ba 1 / 3 Sr 1 / 3 Ca 1 / 3 (Sn) x Ti 1‑x O3, where 0.1≤x≤0.3, the superparaelectric perovskite ceramic material of the A and B sites of the present invention can be used to prepare relaxor ferroelectric materials with good energy storage performance, which meets the current requirements for lead-free production, is environmentally friendly, has a simple process and stable performance, and is conducive to large-scale production.

The application discloses a self-supporting structure deep water transducer based on a relaxor ferroelectric single crystal, which comprises a certain number of transducer units, each of which comprises a piezoelectric element, a transition block, a curved shell, a force transmission plate and a radiation panel; the piezoelectric element adopts a relaxor ferroelectric single crystal element; the curved shell adopts a type VII bending-stretching transducer shell form with the long axis and the short axis vibrating in phase, one force transmission plate is added to the outside of the short axis of the shell, a certain number of transducer units are arranged in a certain rule, the radiation panel is connected to the transducer units through the force transmission plates at both ends of the transducer units, the transverse vibration of the single crystal element is amplified in displacement through the curved shell at the short axis of the shell, the vibration is transmitted to the radiation panel through the force transmission plate, the radiation panel is used for reducing the working frequency, unifying the vibration phase of the transducer units, directly facing the fluid to bear the hydrostatic pressure, and isolating the internal space from the external fluid; the static pressure of the external fluid acts on the radiation panel and then acts on the short axis of the shell through the force transmission plate.

The application provides a lead-free relaxor ferroelectric solid solution and a preparation method thereof. The chemical composition of the lead-free relaxor ferroelectric solid solution is 0.9((1-x)BaTi 0.8 Zr 0.2 O3-xBa 0.65 Sr 0.35 TiO3)-0.1BaTiO3-y% MgO, wherein x represents a molar coefficient, y represents a mass fraction, 0.2<=x<=0.8, and 0 In the application, BZT, BST and BT ferroelectric bodies are combined, the BT ferroelectric body with high polarization intensity is introduced to improve the polarization behavior of the ceramic, and the electric calorimetric variation, the energy storage density and the pyroelectric current of the system are significantly improved; the MgO nano powder is introduced at the interface of the ternary combined lead-free relaxor ferroelectric solid solution, a barrier layer can be formed and an electric field amplification effect can be generated, so that the breakdown field strength is increased, and the electric calorimetry and the energy storage characteristics are improved.

This application relates to a relaxor ferroelectric piezoelectric ceramic material, its preparation method, and its application, belonging to the field of piezoelectric ceramic technology. The method includes: obtaining a ceramic precursor powder after pre-firing, grinding, and drying; preparing the ceramic precursor powder into a casting slurry to form a ceramic green sheet; printing internal electrodes on the ceramic green sheet and performing lamination pressing to obtain a laminated green sheet; hot-cutting the ceramic green sheet to obtain the ceramic green sheet, wherein the internal electrode is an Ag-Pd-Cu ternary metal system, with Ag at 80-90 wt%, Pd at 5-15 wt%, and Cu at 3-8 wt%; performing staged atmosphere co-firing treatment; and performing electrode connection and polarization treatment on the sintered ceramic to obtain a laminated piezoelectric ceramic device. This application synergistically controls the composition of the internal electrode and the sintering atmosphere path, improving the bonding performance of the ceramic-electrode interface, reducing thermal stress concentration, and enhancing the stability and reliability of the laminated piezoelectric ceramic during polarization and use.

The invention discloses a sodium bismuth titanate-based relaxor ferroelectric ceramic material and a preparation method thereof. The chemical formula of the ceramic material is y [(1-x) Bi < 0.5 > Na < 0.5 > TiO < 3-x > Ba < 0.7 > Sr < 0.3 > TiO < 3 >]-(1-y) Ba (Mg < 1 / 3 > Nb < 2 / 3 >) O < 3-z > wt% MO, 0.4, 0.5 < = y < lt >; 1, 0lt; z < = 10; mO is an acidic, amphoteric or low-melting-point oxide; according to the invention, by introducing Ba0. 7Sr0. 3TiO3 and Ba (Mg1 / 3Nb2 / 3) O3, the relaxation characteristic of a system is enhanced, and relatively high energy storage density and efficiency are obtained; particle rearrangement is promoted by using a cold sintering process, atomic clusters or ions in a saturated state can be migrated to pore positions with relatively low chemical potential in a dissolution-precipitation process, the densification process of a ceramic system is remarkably promoted, and the prepared ceramic shows excellent dielectric temperature stability and energy storage efficiency.

The application discloses an iron-based barium sodium niobate ceramic material with high energy storage performance and a preparation method thereof. 4‑2x Sm 2x Na2Fe x Nb 10‑x O 30 , wherein 1<=x<=1.25. Barium carbonate, samarium oxide, sodium carbonate, ferrous oxide and niobium pentoxide are used as raw materials, and a standard solid-phase method is adopted to sinter the iron-based barium sodium niobate ceramic material. In the product formula, iron is used to replace niobium in the barium sodium niobate, which is lead-free, environment-friendly, rich in iron reserves and low in price, and is beneficial to control the cost of raw materials. In addition, the iron replacement is beneficial to enhance the relaxor ferroelectric performance of the material, can obtain a more slender hysteresis loop, and improves the energy storage efficiency of the material. The prepared ceramic material has few pores and cracks, high density, and the microstructure is obviously improved, the grain size is more fine and uniform, the ferroelectric polarization intensity and the breakdown field strength are significantly improved, the problem that the barium sodium niobate material is difficult to sinter is solved, and the ferroelectric performance and the energy storage performance are significantly improved.

The application discloses layered composite lead-free relaxor ferroelectric material and a preparation method thereof, and belongs to the technical field of piezoelectric ceramics, and overcomes the defects that the strain excited by the lead-free relaxor ferroelectric material in the prior art is small under a low driving electric field. The layered composite lead-free relaxor ferroelectric material comprises a first relaxor ferroelectric layer, a ferroelectric layer and a second relaxor ferroelectric layer arranged in sequence; and in the layered composite lead-free relaxor ferroelectric material, 0 < ferroelectric layer mass percentage < 30%. The application provides the layered composite lead-free relaxor ferroelectric material which has low driving electric field and large strain.

The application relates to the technical field of inorganic nonmetal functional ceramic materials, and discloses a polar vortex structure relaxor ferroelectric ceramic material and a preparation method and application thereof, the material is of a chemical formula (1-x)(0.7NaNbO3-0.3Sr 0.7 Bi 0.2 TiO3)-xCaSnO3, wherein 0<=x<=0.2, and a characteristic value is x=0.1. By adopting a step-by-step solid-phase reaction method, NaNbO3, Sr 0.7 Bi 0.2 TiO3 and CaSnO3 ceramic powders are pre-synthesized, then are ball-milled according to a stoichiometric ratio and are sintered into ceramics. The prepared ceramic material has a multi-phase coexistence, core-shell and polar vortex structure, and exhibits high saturation polarization intensity, low hysteresis, large breakdown field strength and excellent service stability, and has potential application in high-power pulse devices. The material is environment-friendly and simple in process, and is expected to provide a new technical path for design and preparation of high-performance and high-stability nonlinear dielectric energy storage materials.

The invention relates to the technical field of phase field simulation, and discloses a transmission imaging simulation method, device and equipment of a polar nanometer microcell and a medium, and the method comprises the following steps: determining a target analysis area of a relaxor ferroelectric sample; performing transmission electron microscope imaging and dark field imaging under diffraction conditions on the target analysis area; based on the dark field image, extracting size distribution and surface density parameters of the polar nanometer micro-area; based on transmission electron microscope imaging, lattice distortion rate parameters of the polar nanometer micro-area are extracted; based on the surface density parameter, determining a simulation concentration value of the reaction-diffusion model; and controlling the reaction-diffusion model to run and simulate a dynamic self-organizing evolution process of the polar nanometer micro-area under set area size and boundary conditions so as to obtain a polar nanometer micro-area aggregation form of the polar nanometer micro-area output by the reaction-diffusion model. According to the scheme, the prediction of the static morphology characterization and dynamic self-organization process of the polar nano micro-area can be realized, and the performance optimization of the relaxor ferroelectric material is improved.

The invention relates to the technical field of piezoelectric materials, and discloses an interface modification-based trigonal phase relaxor ferroelectric single crystal depolarization inhibition method, which comprises single crystal pretreatment, polarization electric field optimization, interface modification layer construction, gradient annealing treatment, stabilization electric field application and protection layer packaging. Through single crystal pretreatment and polarization electric field optimization, it is guaranteed that the surface of a single crystal is smooth and clean, a main polarization electric field is applied in the protective atmosphere through a stepped boosting method, single crystal oxidative damage is avoided, the polarization effect is improved, and a foundation is laid for depolarization inhibition; through construction of an interface modification layer and gradient annealing treatment, a high-dielectric-constant interface layer is formed on the surface of a single crystal, internal stress is eliminated under a protective atmosphere through multi-stage program temperature control annealing, the interface bonding strength and the crystal structure stability are enhanced, and the depolarization process is inhibited.

This invention discloses a method for establishing a phase-field model of a polycrystalline phase relaxor ferroelectric, the method comprising the following steps: 1. Determining the free energy of the polycrystalline phase relaxor ferroelectric; 2. Determining the order parameter of the polycrystalline phase relaxor ferroelectric as spontaneous polarization. P i 3. Represent free energy as spontaneous polarization P i The invention employs several methods: 1) introducing ferroelectric-ferroelectric phase boundaries and random local electric fields; 2) solving the Ginzburg-Landau partial differential equations to obtain the spatial evolution of spontaneous polarization, thereby determining the domain structure of polycrystalline relaxed ferroelectrics and ultimately establishing a phase-field model for polycrystalline relaxed ferroelectrics. Based on a model ferroelectric system, this invention, by considering ferroelectric-ferroelectric phase boundaries and random local electric fields, reproduces the unique domain structure characteristics of polycrystalline relaxed ferroelectrics with the coexistence of multiple nanometer-sized ferroelectric phases, establishes a phase-field model for polycrystalline relaxed ferroelectrics, and improves the theoretical model of polycrystalline relaxed ferroelectrics, which is beneficial for guiding the design of novel high-performance ferroelectric materials.

The invention discloses a relaxor ferroelectric single crystal-based Y waveguide chip integrated structure and a preparation method and application thereof, and the method comprises the steps: sputtering a titanium film on the surface of a PIN-PMN-PT substrate, transferring a Y waveguide pattern to the titanium film after photoetching, carrying out the selective etching of the titanium film after photoetching, forming a Y-type titanium diffusion waveguide pattern, and carrying out the preparation of the relaxor ferroelectric single crystal-based Y waveguide chip integrated structure. The substrate with the Y-type titanium diffusion waveguide pattern and PbO powder are sealed and then subjected to titanium diffusion for 12-36 h at the temperature of 900-1000 DEG C, and then annealing is conducted in the oxygen atmosphere; then depositing a SiO2 buffer layer on the PIN-PMN-PT substrate, etching an electrode contact window pattern, evaporating a gold film on the etched SiO2 buffer layer, and then selectively etching and reserving the gold film corresponding to the electrode contact window pattern as a modulation electrode; and performing optical grinding and polishing and polarization on the end face of the Y waveguide chip. According to the invention, the PIN-PMN-PT single crystal is taken as the substrate, and an optimized titanium diffusion and electrode preparation process is combined, so that the Y waveguide device with low half-wave voltage, low transmission loss and high temperature stability is prepared, and the Y waveguide device can be applied to a spaceflight-level fiber-optic gyroscope system.

The invention belongs to the field of semi-solid batteries, and particularly relates to a modified relaxor ferroelectric polymer, a modified semi-solid electrolyte, a preparation method and application of the modified relaxor ferroelectric polymer and the modified semi-solid electrolyte, and a battery. A polymer chain of the polymer modified intermediate is modified with double bonds, and then the polymer modified intermediate and a modifier are polymerized to prepare the modified relaxor ferroelectric polymer; the modifier is represented by formula 1 (). The relaxation polymer is innovatively subjected to dehalogenation treatment and then innovatively subjected to combined polymerization with the formula 1, so that the polymerization behavior and the polymerization structure can be regulated and controlled, the relaxation polymer accidentally adapts to the application requirements of the semi-solid electrolyte, the flowability of the electrolyte can be effectively bound, the electrochemical window of the liquid electrolyte is improved, and the growth of lithium dendrites on the negative electrode side is inhibited; and thus, the high-pressure resistance, the high-temperature resistance stability and the long cycle performance of the semi-solid polymer electrolyte are improved.

The invention belongs to the field of ceramic materials, and particularly relates to a lead-free ferroelectric ceramic material and a preparation method thereof.The preparation method comprises the steps that aluminum nitrate nonahydrate and titanium isopropylate are dissolved in ethylene glycol and stirred, a citric acid solution is added, stirring continues, and a precursor solution A is prepared; dissolving bismuth nitrate pentahydrate in a citric acid solution, and stirring to prepare a precursor solution B; mixing the precursor solution A and the precursor solution B, stirring and drying to form gel; drying, grinding and crushing the gel, and calcining to obtain ceramic powder; the preparation method comprises the following steps: uniformly mixing ceramic powder and nano barium titanate powder by taking deionized water as a medium, and drying to obtain precursor powder; grinding and granulating the precursor powder and a 5wt% polyvinyl alcohol solution in an agate mortar, and then applying axial pressure to form a green body; and putting the green body into a corundum crucible with a cover, and sintering by using a two-step method to finally obtain the lead-free ferroelectric ceramic material. According to the invention, a universal combined optimization strategy is provided, and a strong relaxation ferroelectric system is developed.

The application relates to a lead-free ceramic and a preparation method and a capacitor thereof, and belongs to the technical field of ceramics; BKT ceramic is solid-solved into ST ceramic, the paraelectric phase in the ST ceramic is broken by introducing the BKT ceramic, and the relaxation characteristic is improved. Meanwhile, BZT ceramic is introduced, the sintering temperature of the whole body is reduced, and then the probability of forming a liquid phase of the ceramic during sintering is reduced. The introduction of the BZT ceramic can make the micro-ordering of the ceramic become disordered, finally forming a bicrystal site disordered relaxor ferroelectric, and then being beneficial to the power density of the lead-free ceramic. In addition, the grain size of the BKT ceramic is small, the reduction of the grain size reduces the number of oxygen vacancies, the oxygen vacancies are oxidized again in the sintering process, the oxygen vacancies are further reduced, the grain growth is inhibited by the fewer oxygen vacancies, finally leading to the reduction of the grain size, more grain boundaries can be formed, so that the lead-free ceramic has a higher breakdown field strength and is beneficial to the improvement of the energy storage performance of the material.

The present invention belongs to the technical field of ceramics, and discloses a sodium bismuth titanate-based lead-free relaxor ferroelectric ceramic with high energy storage, its preparation method and application. The chemical formula of the ferroelectric ceramic is (1-x)(0.7Na 0.5 Bi 0.5 TiO3 - 0.3Sr 0.7 Bi 0.2 TiO3) - xBi(Mg 0.5 Zr 0.5 )O3, where 0 < x ≤ 0.18. This ceramic has good temperature stability, frequency stability, a large saturation polarization intensity, a low remanent polarization intensity, and a higher breakdown field strength. The energy storage density of the ferroelectric ceramic of the present invention is 4.7 J / cm 3 or more, and the energy storage efficiency is 75% or more, which is suitable for high-power pulse devices.

This invention relates to the field of relaxor ferroelectric ceramic dielectric energy storage materials, specifically to a sodium bismuth titanate-based relaxor ferroelectric ceramic and its preparation method, wherein the chemical composition of the sodium bismuth titanate-based relaxor ferroelectric ceramic is (1-x)BNLT. ‑x BAN, of which BNLT is 0.9Bi 0.5 Na 0.5 TiO3-0.1Bi 0.5 Li 0.5 TiO3, BAN is BaAl 0.5 Nb 0.5 The value of O3 and x ranges from 0.06 to 0.18. When x = 0.15, the ceramic exhibits excellent performance with a recoverable energy storage density (Wrec) of not less than 14.0 J / cm³ and an energy storage efficiency (η) of not less than 84% under an electric field of 775 kV / cm. This invention employs a solid-state reaction sintering process, which is simple to prepare and low in cost, making it suitable for high-performance energy storage capacitors in pulsed power systems.

The invention relates to the technical field of ferroelectric liquid crystals, in particular to a relaxor ferroelectric / anti-ferroelectric liquid crystal material and a preparation method and application thereof. The relaxor ferroelectric / anti-ferroelectric liquid crystal material provided by the invention retains the ferroelectricity of ferroelectric nematic phase liquid crystal, generates isotropic-ferroelectric phase transition at 43.3 DEG C, and shows the specific ferroelectric hysteresis loop and dielectric relaxation behavior of the relaxor ferroelectric.

The application relates to the technical field of dielectric energy storage device materials, in particular to a high-entropy design bismuth ferrite-based energy storage ceramic, a preparation method and application thereof, the material has a chemical composition formula of (0.7-x)Bi 0.9 (Sm 0.5 Gd 0.5 ) 0.1 FeO3-0.3(Sr 0.5 Ba 0.5 )TiO3-xNaNbO3-yMnO2, wherein the value range of x is 0-0.15, and the value of y is 0-0.005. The application adopts a high-entropy strategy to design a relaxor ferroelectric material, multiple elements occupy the same site of the material to produce lattice distortion, promote the relaxor characteristics of the bismuth ferrite-based ceramic, and optimize the electric hysteresis loop. The NaNbO3 antiferroelectric material is introduced to destroy the long-range ferroelectric order and enhance the local random field, which is beneficial to obtaining a lower P r value. In addition, the appropriate addition of 0.5% mol of MnO2 can reduce the concentration of oxygen vacancies, thereby reducing the leakage current of the material, and the energy storage efficiency is improved. The material design not only enriches the application field of high-entropy ceramics, but also provides a new idea for improving the performance of energy storage ceramics.

The invention discloses a high-performance large-size 1t; 111gt, 111gt; the invention relates to a c-oriented PST single crystal and a preparation method thereof, and belongs to the technical field of relaxor ferroelectric crystal materials, the preparation method comprises the following steps: filling PST-cosolvent mixed powder into a platinum crucible with a cover, compacting and sealing, putting the platinum crucible into a crystal growth furnace, and using a corundum crucible, the whole crystal growth process being an oxygen introduction mode; growing in a high-purity oxygen protection atmosphere at the temperature of 1220-1250 DEG C by adopting a cosolvent method, regulating and controlling the degree of supercooling through gradient cooling, and growing the pseudo-cubic PST crystal until the size is not smaller than a set size; the atmosphere in the furnace is switched into argon protection, and the temperature is reduced to the room temperature in a segmented gradient mode; performing staged ordered annealing treatment on the crystal to obtain an annealed pseudo-cubic PST crystal; performing cutting, crystal orientation, grinding and polishing on the annealed pseudo-cubic PST crystal in sequence to obtain 1t; 111gt, 111gt; c, orienting the PST single crystal; large-size growth is realized, and B-site ions are highly ordered; 111gt, 111gt; and c, coordinated regulation and control of accurate orientation acquisition.

In embodiments of the present disclosure, a field effect transistor includes a ferroelectric gate dielectric layer with a relaxor ferroelectric material. The relaxor ferroelectric may include, for example, (BaxCa(1-x))(TiyZr(1-y))O3, a solid solution of BiFeO3 and BTO, BaZrxTi(1-x)O3, or BaNbxTi(1-5x / 4)O3.

The present application relates to the technical field of material, and discloses a method for enhancing the electrostriction of sodium bismuth titanate-based relaxor ferroelectric.The present application induces the original large-size non-percolating polar region in the percolating sodium bismuth titanate-based relaxor by pre-polarizing the sodium bismuth titanate-based relaxor ferroelectric ceramic near the critical position synthesized by the traditional solid-phase method, reduces the nucleation barrier in the field-induced strain process, and significantly enhances the electrostriction effect.The sodium bismuth titanate-based relaxor ferroelectric ceramic of the present application has obviously improved electrostriction under the excitation of 60 kV / cm electric field compared with the initial state, and has more excellent performance than the ordinary sodium bismuth titanate-based relaxor ferroelectric ceramic.

The invention relates to the technical field of inorganic nonmetal functional ceramic materials, and discloses a dislocation-induced polar vortex structure relaxor ferroelectric ceramic material as well as a preparation method and application thereof, the chemical formula of the material is (1-x) Ba < 0.5 > Bi < 0.5 > Ti < 0.5 > Fe < 0.5 > O < 3-x > Ca < 0.7 > La < 0.2 > ZrO < 3 >, x is greater than or equal to 0 and less than or equal to 0.2, and the characteristic value is x = 0.1. The preparation method comprises the following steps: synthesizing Ba0. 5Bi0. 5Ti0. 5Fe0. 5O3 and Ca0. 7La0. 2ZrO3 ceramic powder in advance by adopting a step-by-step solid-phase reaction method, carrying out ball-milling mixing according to a stoichiometric ratio, and sintering to obtain the ceramic. The prepared ceramic material has two-phase coexistence, high-concentration double-charge oxygen vacancies, dislocation lines penetrating through a core-shell layer and a polar vortex structure, shows high saturation polarization intensity, low hysteresis, large breakdown field strength and excellent service stability, and has potential application in high-power pulse devices.

The invention relates to the technical field of functional film material preparation, and discloses a preparation method of a relaxor (anti) ferroelectric material. Aiming at the problems of difficulty in component control, complex components and the like of the traditional relaxor ferroelectric, the relaxor (anti) ferroelectric film material is prepared by adopting a Joule heat (electromagnetic induction) flash heating and liquid nitrogen quenching synergistic process, and the preparation method comprises the following specific steps: spin-coating a precursor solution on a conductive substrate to obtain a raw material film; drying the prepared raw material film in a muffle furnace at 450 DEG C for 3 minutes; the Pb (Zr < 1-x > Ti < x >) O < 3 > amorphous film with the required thickness is prepared; and then heating to 650 DEG C at a heating rate of 1000 DEG C / s, annealing, and carrying out liquid nitrogen quenching cooling on the annealed amorphous film. According to the method, the film preparation efficiency is greatly improved, and the production energy loss is greatly reduced.

The application relates to the technical field of piezoelectric materials, and discloses a method for inhibiting depolarization of a trigonal phase relaxor ferroelectric single crystal based on interface modification, which comprises single crystal pretreatment, polarization electric field optimization, interface modification layer construction, gradient annealing treatment, stable electric field application and protective layer packaging. Through single crystal pretreatment and polarization electric field optimization, the surface of the single crystal is ensured to be smooth and clean, a step-by-step boosting method is adopted to apply a main polarization electric field in a protective atmosphere, oxidation damage of the single crystal is avoided, and the polarization effect is improved, thereby laying a foundation for inhibiting depolarization. Through interface modification layer construction and gradient annealing treatment, a high dielectric constant interface layer is formed on the surface of the single crystal, internal stress is eliminated in a protective atmosphere through multi-stage program temperature annealing, the interface bonding strength and the crystal structure stability are enhanced, and the depolarization process is inhibited.

This invention relates to the field of dielectric energy storage ceramic materials, specifically to a CaTiO3-based relaxor ferroelectric ceramic material and its preparation method. The general chemical formula of the CaTiO3-based composite relaxor ferroelectric ceramic material is: (1-x)Ca 0.5 Bi 0.25 Na 0.25 TiO3-xBaZrO3, where 0 < x ≤ 0.30, is produced by solid-state reaction method, in which Bi2O3, Na2CO3, CaCO3, TiO2, BaCO3, and ZrO2 are stoichiometrically proportioned, followed by wet ball milling, pre-calcination, granulation, tableting, debinding, and sintering. This invention, by constructing a relaxor ferroelectric heterojunction, synergistically optimizes the breakdown field strength, polarization intensity, and dielectric loss, solving the problems of polarization saturation and low energy storage efficiency in traditional ferroelectrics.

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.

The application discloses a high-performance relaxor ferroelectric single crystal and a preparation method and application thereof, and belongs to the technical field of piezoelectric materials. Based on a TSSG method, through the synergistic effect of a bottom oxygen feeding technology and component regulation, a technical problem that a piezoelectric charge coefficient d 33 and a piezoelectric voltage coefficient g 33 are difficult to be considered simultaneously in the existing relaxor ferroelectric single crystal is successfully solved. The bottom oxygen feeding technology effectively inhibits Pb element volatilization and compensates oxygen vacancies, greatly reduces the defect density and the content of impurities in the crystal, and eliminates the pinning effect of defect dipoles on domain switching. In combination with accurate construction of a morphotropic phase boundary, the single crystal can fully release the polarization deflection advantage caused by the coexistence of multiple phases. The prepared PYN-PMN-PT relaxor ferroelectric single crystal realizes the coexistence of high piezoelectric response and excellent piezoelectric voltage coefficient, and significantly improves the quality factor of the material.