80 results about "Potassium niobate" patented technology

The present invention belongs to the technical field of ceramic material preparation methods, and specifically relates to a lead-free piezoelectric ceramic, its preparation method, and application. The lead-free piezoelectric ceramic is a KNN-based lead-free piezoelectric ceramic or a BT-based lead-free piezoelectric ceramic having a perovskite structure; the KNN-based lead-free piezoelectric ceramic is prepared by doping gallium nitride with potassium sodium niobate (KNN) ceramic as the matrix, and the chemical formula is 0.955 (K 0.48 Na 0.52 )Nb 0.98 Sb 0.02 O3‒0.045Bi 0.5 Na 0.5 ZrO3‒0.75mol% GaN; The BT-based lead-free piezoelectric ceramic is prepared by doping gallium nitride with barium nitride (BT) as the matrix, and the chemical formula is (Ba 0.85 Ca 0.15 )(Ti 0.9 Zr 0.1 ) O‒1.75mol% GaN; the lead-free piezoelectric ceramic has a dense structure, is lead-free, and exhibits excellent electrochemical properties. The preparation method for the lead-free piezoelectric ceramic is simple, low-cost, pollution-free, and utilizes readily available raw materials. The lead-free piezoelectric ceramic can be used to prepare energy harvesters and has significant application value.

The invention provides a fabric-reinforced electroactive nerve conduit and a preparation method and application thereof, and belongs to the field of biomedical materials.The fabric-reinforced electroactive nerve conduit comprises a nerve conduit inner layer and a nerve conduit outer layer, the nerve conduit inner layer is a woven skeleton formed by magnesium wires serving as parallel yarns and degummed silk through a three-dimensional weaving process, the pore diameter of the nerve conduit inner layer is 1.5-2 mm, and the thickness of the nerve conduit inner layer is 0.5-1 mm; the outer layer of the nerve conduit is a composite layer with a radial finger-shaped porous structure, which is formed by directionally freezing and casting a hydrogel cross-linked network formed by mixing potassium sodium niobate nanorods modified by polydopamine and a biopolymer material, and the thickness of the outer layer of the nerve conduit is 1-2mm. A three-dimensional weaving technology, a piezoelectric nano material and a biopolymer material are combined, a novel multifunctional nerve conduit is developed to repair nerve injury, a better solution is provided for nerve repair, and the fabric enhanced electric activity nerve conduit has important practical guiding significance in application of future clinical nerve injury repair.

The piezoelectric ceramic according to the present disclosure includes, as a main component, a sodium potassium niobate-based composition. The composition is represented by general formula (1). General formula (1): {(K1-a-bNaaLib)1-c-dA1cA2d} x {(Nb1-e- fTaeSbf)1-g-hB1gB2h}O3. Further, the piezoelectric ceramic according to the present disclosure contains, with respect to 100 parts by mass of the abovementioned composition, Mn in the amount of 0.05 to 3.50 parts by mass in terms of MnO2.

The invention discloses a preparation method of a potassium-sodium niobate-based single crystal, the chemical formula of the potassium-sodium niobate-based single crystal is # imgabs0 # x representing the mole fraction of Co element in a system, 0 < x < = 0.005, pre-seed crystals prepared by a seed-crystal-free solid-phase crystal growth method are subjected to surface growth residue and attachment removal, polishing, thinning and related treatment, and the potassium-sodium niobate-based single crystal is obtained. According to the method, the potassium-sodium niobate and the powder are pressed together to form a seed burying blank, the large-size potassium-sodium niobate-based single crystal grows through seed crystal induction, the advantages of a seed crystal-free solid phase method and a traditional solid phase method are combined, the stability of single crystal growth is ensured, and regulation and control of the growth orientation and size increase of the single crystal can be realized through accurate control of the seed crystal; the introduction of impurities can be avoided, and the repeatability and stability of single crystal growth are improved.

The invention discloses a high-performance lead-free piezoelectric catalytic material and a preparation method and application thereof, and belongs to the field of catalytic materials and pollution abatement, the preparation method of the lead-free piezoelectric catalytic material comprises the following steps: weighing K2CO3, Na2CO3, Nb2O5, Fe2O3 and Co2O3, mixing, performing ultrasonic dispersion treatment, and then performing grinding and presintering treatment to obtain precursor powder; grinding the precursor powder again, and then tabletting to obtain a green body; the green body is subjected to sintering treatment and grinding treatment in sequence, and ceramic powder is obtained; the ceramic powder is placed in pure water for ultrasonic treatment, then drying treatment is conducted, and the lead-free piezoelectric catalytic material is obtained. The potassium-sodium niobate-based lead-free piezoelectric catalytic material prepared through the processes of compact sintering, grinding, pure water ultrasonic treatment and the like has extremely high spontaneous polarization, has a very obvious effect on piezoelectric catalytic degradation of rhodamine B, and has the advantages of being environmentally friendly, efficient, high in catalytic activity, safe, stable, capable of reacting at normal temperature and the like.

The potassium sodium niobate-based ceramic material with excellent fatigue resistance disclosed in the present invention has a general chemical composition formula of: (1-x)K 0.5 Na 0.5 NbO3‑x(Sr 0.7 La 0.2 )(Mg 1 / 3 Nb 2 / 3 )O3; x represents the number of moles, and x is 0.03 to 0.12; the ceramic has a perovskite structure, a breakdown electric field of 230 to 400 kV / cm, and a maximum polarization strength of 29.6 to 34.1 μC / cm 2 , the residual polarization intensity is 4.1~7.4μC / cm 2 The present invention discloses a method for preparing a potassium sodium niobate-based ceramic material with excellent fatigue resistance, comprising the following steps: batching, primary ball milling, pre-sintering, secondary ball milling, tableting, cold isostatic pressing, and pressureless closed sintering. The potassium sodium niobate-based ceramic material of the present invention exhibits excellent energy storage performance and fatigue resistance. The ceramic material preparation method of the present invention is simple, reproducible, and has a high yield.

The invention discloses a barium carbonate doped potassium-sodium niobate-based piezoelectric single crystal and a preparation method thereof, the barium carbonate doped potassium-sodium niobate-based piezoelectric single crystal has a chemical general formula of (1-x) (K < 0.498 > Na < 0.498 > Li < 0.004 > Nb < 0.9955 > Bi < 0.004 > Fe < 0.0005 > O < 3 >)-xBaCO3, 0.001 < = x < = 0.009, and x represents a mole fraction. The preparation method comprises the following steps: taking Na2CO3, K2CO3, Nb2O5, Li2CO3, Bi2O3, BaCO3 and Fe2O3 as raw materials, adopting a seedless solid-phase crystal growth method, and carrying out primary refinement ball milling, pre-sintering, secondary refinement ball milling and sintering to prepare the barium carbonate doped potassium sodium niobate based single crystal. According to the method, the collaborative optimization of the piezoelectric property and the temperature stability is realized while the growth of the large-size single crystal is ensured.

The invention relates to the technical field of photocatalysis, in particular to a copper and titanium co-doped potassium niobate photocatalytic material and a preparation method thereof. Potassium niobate is partially substituted in the synthesis stage of potassium niobate through a hydrothermal method, the crystal structure of potassium niobate can be kept stable after doping, the light absorption range is widened, and the photocatalytic efficiency is improved. Other potassium niobate doped photocatalytic materials are difficult to consider both the performance and the practicability due to the problems of structural defects, charge imbalance, insufficient light absorption or poor stability and the like. Cu-Ti co-doping achieves breakthrough in the aspects of band gap regulation and control, charge separation and structural stability through a complementary mechanism, the peak value of transient photocurrent response and steady-state output are remarkably improved, and the optimal solution of potassium niobate modification is achieved.

An object of the present disclosure is to provide a dense potassium sodium niobate sintered body and a sputtering target capable of producing a thin film having a desired composition and crystal phase. A potassium sodium niobate sintered body containing potassium (K), sodium (Na), niobium (Nb), and oxygen (O) satisfies 1 < (K+Na) / Nb ≤ 1.3 in terms of atomic ratio, and has a dimensional density of 3.9 g / cm 3 The above.

The invention discloses a magnetic element modified potassium niobate-based spiral electric polarization ceramic and a preparation method thereof. The chemical composition is (1-x) KNbO3-xFe2O3, wherein x is more than or equal to 0.0005 and less than or equal to 0.002. The preparation method comprises the following steps: weighing K2CO3, Nb2O5 and Fe according to a stoichiometric ratio, grinding, pre-sintering and ball-milling to obtain raw material powder, pressing the powder into sheets by using a mold, and sintering at 1030-1040 DEG C for 2 hours to obtain the iron element modified potassium niobate-based ceramic. The preparation method disclosed by the invention is simple in preparation steps, green, friendly and high in repeatability, has a spiral electric polarization characteristic similar to that of a liquid crystal material, and has the comprehensive performance ranges of high energy storage efficiency of 96.60-97.87% and breakdown field strength of 110-440kV / cm under different proportions. The lead-free functional inorganic material has great commercial application value.

This piezoelectric element comprises a columnar laminate and two conductor layers. In the columnar laminate, internal electrodes and a piezoelectric body having potassium sodium niobate as the main component are alternately laminated. The two conductor layers are positioned on the respective lateral surfaces of the laminate and are connected to the corresponding internal electrodes. The piezoelectric body has a first portion and a second portion. The first portion overlaps the internal electrodes in a planar perspective view in the lamination direction. The second portion is located outside the first portion and does not overlap the internal electrodes in the planar perspective view. The concentration of at least one of potassium and sodium contained in the piezoelectric body is constant in the first portion, decreases stepwise at the interface between the second portion and the first portion, and decreases gradually from the interface to the surface in the second portion.

The present application relates to the technical field of photoelectric functional crystal materials, in particular to a preparation method of tetragonal transparent potassium tantalum niobate crystal, comprising the following steps: (1) plating electrodes on the surface of the crystal; (2) controlling the temperature of the potassium tantalum niobate crystal with plated electrodes to be within the range of 2-6 ℃ below the Curie point and keeping it constant all the time; (3) polarizing the crystal by applying an alternating electric field under ultraviolet laser irradiation to obtain the tetragonal transparent potassium tantalum niobate crystal. The potassium tantalum niobate crystal prepared by the method can maintain a transparent state for a long time without a large thermal shock, solving the problem that the tetragonal potassium tantalum niobate crystal cannot be applied in the field of electro-optical modulation due to low light transmittance, and also solving the problem of light scattering caused by micro-domain walls of the cubic potassium tantalum niobate crystal near the Curie point.

A polymer composite having piezoelectric properties that can be formed for flexible and / or thin film applications, where the polymer composite includes a polymer matrix and a piezoelectric ceramic filler embedded in the polymer matrix. The polymer matrix can include at least two polymers: a first polymer and a second polymer. The first polymer can be a fluorinated polymer and the second polymer can be compatible with the first polymer and have a dielectric constant less than about 20. The piezoelectric ceramic filler can be lithium-doped potassium sodium niobate (KNLN) and can be about 40-70 vol% of the polymer composite. The remaining 30-60 vol% can be the polymer matrix, which itself can be about 5-20 wt% of the second polymer and 80-95 wt% of the fluorinated polymer.

Provided is a thin-film piezoelectric device having excellent piezoelectric characteristics and a large amount of displacement. The thin film piezoelectric device includes a substrate and a movable portion supported by the substrate. The movable part is provided with at least a buffer film that is provided on the substrate and contains zirconium oxide (ZrO2), a first electrode layer that is provided on the buffer film, a piezoelectric film that is provided on the first electrode layer, and a second electrode layer that is provided on the piezoelectric film. The piezoelectric film is formed by lead zirconate titanate (Pb (Zr, Ti) O3; pZT), barium titanate (BaTiO3; bT) or potassium sodium niobate ((K, Na) NbO3; the (001) or (100) alignment film is composed of a single crystal of (001) or (KNN). The piezoelectric film in the movable part expands and contracts in an in-plane direction in association with a d31 mode based on a piezoelectric or inverse piezoelectric effect, whereby the movable part moves, and an angle [theta] between the in-plane direction in which the displacement of the movable part is maximized and a < 100 > orientation of the piezoelectric film is within + / -11.5 DEG.

The present application relates to a potassium sodium niobate based textured piezoelectric ceramic with high Curie temperature and temperature stability, and a preparation method thereof, the textured piezoelectric ceramic has a general chemical formula of (0.99-x)((K 0.5 Na 0.5 )(Nb 0.98 Ta 0.02 )O3)‑0.01(Bi(Ni 0.67 Nb 0.33 )O3)‑x(Bi 0.5 K 0.5 )HfO3+3wt.%NaNbO3, 0≤x≤0.04; the method comprises a solid phase synthesis method, a two-step molten salt method combined with a separation method, a template grain growth method, a casting process, a hot pressing process, a glue removal process, a two-step sintering process, a silver sintering process and a polarization process. Compared with the prior art, the present application can obtain a lead-free textured piezoelectric ceramic with high Curie temperature and high piezoelectric performance by the solid phase synthesis method, the template grain growth method combined with the casting process and the two-step sintering process, more importantly, the ceramic exhibits a single tetragonal phase structure, has high positive and inverse piezoelectric coefficients, and the piezoelectric coefficient and the inverse piezoelectric coefficient have small change rates in a wide temperature range, and has excellent temperature stability.

The application discloses a kind of biphasic bioactive tissue repair scaffolds and preparation method, comprising the following steps: step 1: calcium phosphate ceramic powder is modified on surface, and the modified calcium phosphate ceramic powder is obtained;Step 2: the modified calcium phosphate ceramic powder, potassium sodium niobate piezoelectric ceramic powder, dispersing agent, photoinitiator, photosensitive resin are mixed evenly, and the light-cured resin slurry is obtained after ball milling;Step 3: according to the design, 3D printing model is constructed, and the light-cured resin slurry is printed according to 3D printing model, and the scaffold body can be obtained;Step 4: scaffold body is cleaned, and the required scaffold can be obtained after defatting sintering;The application can prepare biphasic bioactive tissue repair scaffold with good mechanical properties, efficient antitumor ability and better bone regeneration capacity, and provide technical support for the repair of bone tumor postoperative bone defect in clinic.

This invention provides a modified ferroelectric polymer composite film, its preparation method, and its applications, belonging to the field of piezoelectric composite material technology. The modified ferroelectric polymer composite film includes a ferroelectric polymer base film and a plurality of composite nanoparticles and multi-walled carbon nanotubes dispersed within the ferroelectric polymer base film. The composite nanoparticles have a core-shell structure, comprising a core and an inner shell layer and an outer shell layer sequentially surrounding the core. The core comprises a composite piezoelectric ceramic material composed of potassium sodium niobate and barium titanate, the inner shell layer comprises polydopamine, and the outer shell layer comprises MnO2. This invention fully utilizes the synergistic effect of the composite nanoparticles and multi-walled carbon nanotubes on the dielectric and piezoelectric properties of P(VDF-TrFE) materials, thereby preparing a composite material with high dielectric constant, low dielectric loss, and excellent piezoelectric properties to meet the stringent performance requirements of high-performance sensors and other application fields.

The application relates to the technical field of piezoelectric ceramic devices, and particularly discloses a super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic with a chemical formula of (1-x)(Na 1‑y K y ) z Nb 1‑h Ta h O3-xAZr t O3+i% M+k% N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04<=x<0.08, 0.45

The application relates to a potassium-sodium niobate-based lead-free piezoelectric ceramic, the components of the potassium-sodium niobate-based lead-free piezoelectric ceramic are (1-x)K 0.48 Na 0.55 Bi a Nb 0.96 Zr b Sb c O3-a-b-c-CuOx; wherein 0.01<=a<=0.08, 0.02<=b<=0.08, 0.02<=c<=0.08, 0.001<=x<=0.2, x represents the molar fraction of CuO, the application can effectively improve the ceramic oxygen vacancy concentration and enhance the pinning effect of the ceramic ferroelectric domain wall by regulating the proportion of copper oxide, so that a potassium-sodium niobate-based lead-free piezoelectric ceramic with moderate d 33 And high mechanical quality factor Qm is obtained, which is expected to be applied in the field of lead-free medium-power piezoelectric devices. In addition, the process for preparing the potassium-sodium niobate-based lead-free piezoelectric ceramic is simple, the cost is low, and the application has the potential for industrial application.

The invention relates to the field of dielectric energy storage ceramic materials, in particular to potassium-sodium niobate-based energy storage ceramic as well as a preparation method and application thereof. The chemical composition of the potassium-sodium niobate-based energy storage ceramic comprises (1-x) (0.55 K0. 5Na0. 5NbO3-0.45 BaTiO3)-x (Bi0. 5yNa0. 5 + y) Ti0. 9Zr0. 1O3, x is more than 0 and less than or equal to 0.4, and y is more than or equal to-0.05 and less than or equal to 0.1. The potassium-sodium niobate-based energy storage ceramic still keeps excellent energy storage efficiency while having high energy storage density, and can meet the use requirements to a greater extent, specifically, at the room temperature of 100 Hz, the energy storage density of the potassium-sodium niobate-based energy storage ceramic is 7.02 J / cm < 3 >-10.55 J / cm < 3 >, and the energy storage efficiency is 91.7%-94.2%.

The invention relates to the technical field of thin-film capacitor materials, and discloses a temperature-adaptive thin-film capacitor material and a manufacturing method thereof, and the temperature-adaptive thin-film capacitor material comprises a polyetherimide substrate thin film as a substrate support and barium titanate potassium niobate composite ceramic particles, the barium titanate potassium niobate composite ceramic particles are uniformly distributed in the polyetherimide substrate film in a discrete mode, the polyetherimide substrate film internally contains a dispersing agent and an antioxidant, and the dispersing agent is distributed in a PEI molecular chain of the polyetherimide substrate film and in an interface area of the barium titanate potassium niobate composite ceramic particles. And antioxidant molecules are uniformly embedded among PEI molecular chains of the polyetherimide substrate film and cannot be chemically bonded with PEI and the composite ceramic particles. According to the temperature self-adaptive thin film capacitor material and the manufacturing method, compatibility is improved, agglomeration is prevented, and dielectric loss is reduced; the antioxidant is embedded into a PEI molecular chain, oxidative degradation of the PEI molecular chain is inhibited, long-term stability is guaranteed, loss is reduced, the service life is prolonged, and product consistency is guaranteed.

The application provides a double-rare earth doped photoelectric storage film and a preparation method and application thereof, and the method comprises the following steps: (1) pressing Eu2O3 and Tb4O7 into sheet structures respectively, obtaining Eu2O3 target material and Tb4O7 target material after high-temperature calcination; and placing the Eu2O3 target material and the Tb4O7 target material on a KNN target material to simultaneously perform radio frequency sputtering, and obtaining a photoelectric storage film. The photoelectric storage film of the double-rare earth doped potassium sodium niobate prepared by the application has high transparency, full-waveband fluorescent reading, good stability and bending resistance, and can realize coupling between photochromism and dielectric energy storage in the film material, thereby providing a new opportunity for the application requirement of constructing a future flexible foldable photoelectric storage device.

The invention provides a lead-free piezoelectric ceramic material, a preparation method thereof and a piezoelectric device. The lead-free piezoelectric ceramic material is represented by a chemical general formula as follows: (1-x-y) (K1-aNaa) (Nb1-bMb) O < 3-x > AWO < 4-y > BMoO < 4 >, wherein (K1-aNaa) (Nb1-bMb) O3 represents a potassium-sodium niobate-based ceramic material, a is greater than or equal to 0.4 and less than or equal to 0.6, b is greater than or equal to 0 and less than or equal to 0.1, and M is a doped metal element; x and y are mole fractions and satisfy 0 lt; x is less than or equal to 0.05, 0lt; y is less than or equal to 0.05, and 0 lt; x + y < = 0.1; the AWO4 is tungstate, and the BMoO4 is molybdate. Through the synergistic effect of tungstate and molybdate, the sintering temperature of the lead-free piezoelectric ceramic material is reduced, the piezoelectric constant of the lead-free piezoelectric ceramic material is improved, the dielectric loss of the lead-free piezoelectric ceramic material is reduced, the comprehensive performance of the lead-free piezoelectric ceramic material is greatly improved, and the lead-free piezoelectric ceramic material can be applied to piezoelectric devices such as piezoelectric motors with high requirements for piezoelectric performance.

The invention discloses a melt spinning preparation method of a flexible piezoelectric fiber with a core-sheath structure, and relates to the field of electronic materials and sensors. The problems of rigidity and brittleness of an existing piezoelectric material are solved. The preparation method comprises the following steps: mixing and stirring potassium sodium niobate piezoelectric powder, polylactic acid powder and a titanate coupling agent, banburying at a high temperature, and carrying out melt spinning, evaporation of an external copper electrode and polarization treatment by using a coaxial spinning nozzle and a copper wire to prepare the flexible piezoelectric fiber with a core-sheath structure. The fiber takes potassium sodium niobate as a piezoelectric active material, the core part is a copper wire, the outer layer is an evaporation copper layer with the thickness of 100-200nm, and the diameter is 50-200mu m. An electrode structure can be arranged in the fiber core part, so that an electric signal can be conveniently obtained; and the selected polylactic acid material has degradability and biocompatibility, so that the fiber can be applied to the field of biomedical sensors, is low in treatment difficulty after being discarded, and has wide application prospects in the fields of intelligent fabrics, intelligent robots with bodies and the like.

The invention belongs to the technical field of material science and engineering, and particularly discloses an optimization method for improving the piezoelectric property of a KNN crystal based on composite polarization, and the method comprises the following steps: S1, polishing the potassium sodium niobate crystal, and plating Au electrodes on the upper and lower surfaces of the potassium sodium niobate crystal to obtain an initial material body; s2, putting the initial material body obtained in the step S1 into a crucible filled with silicone oil, and carrying out heating direct current polarization treatment to obtain a polarized material body; s3, putting the polarized material body obtained in S2 into a potassium iodide solution, then polishing, and plating Au electrodes on the upper surface and the lower surface of the polarized material body again to obtain an intermediate material body; and S4, performing normal-temperature alternating-current polarization treatment on the intermediate material body obtained in S3 to obtain the composite polarization material body. According to the optimization method for improving the piezoelectric property of the KNN crystal based on the composite polarization, the piezoelectric property of the KNN crystal is remarkably improved, the required cost is low, the consumed time is short, and practical application and popularization are easier.

The present invention discloses a flexible piezoelectric micromechanical ultrasonic transducer and its preparation method and application. The flexible piezoelectric micromechanical ultrasonic transducer of the present invention includes a laminated structure and a flexible coating layer that encapsulates the laminated structure. The laminated structure includes a flexible substrate, an adhesive layer, a first supporting layer, a second supporting layer, a bottom electrode layer, a piezoelectric layer and a top electrode layer that are stacked in sequence. The first supporting layer is provided with a through-cavity structure. The first supporting layer and the second supporting layer are both made of epoxy-based negative photoresist. The composition of the piezoelectric layer includes polyvinylidene fluoride-trifluoroethylene and nano potassium sodium niobate ceramic particles. The flexible piezoelectric micromechanical ultrasonic transducer of the present invention has the advantages of high sensitivity, good tensile ductility and bending properties, flexible adjustment of resonant frequency, and easy arraying. In addition, its preparation method is simple, the production cost is low, and it is easy to mass produce, and it is suitable for large-scale industrial production and application.

This invention relates to the field of piezoelectric materials and discloses a method for preparing a potassium sodium niobate thin film. The method involves first synthesizing a ceramic target material from niobium pentoxide, potassium carbonate, and sodium carbonate in a solid phase; then placing the ceramic target material in a magnetron sputtering apparatus for sputtering to form an amorphous thin film; finally, adding the amorphous thin film to an annealing atmosphere in a crucible for annealing to form a potassium sodium niobate thin film. This method uses magnetron sputtering to prepare an amorphous potassium sodium niobate thin film under conditions below the film crystallization temperature, followed by annealing to crystallize the film. During annealing, an alkali metal atmosphere is used to compensate and control the alkali metal elements in the film. This method is still based on magnetron sputtering, which is suitable for large-size thin film growth, offering strong process controllability and high production efficiency. The alkali metal atmosphere compensation allows for control of the alkali metal element composition in the potassium sodium niobate.

The invention relates to the field of piezoelectric ceramic materials, in particular to potassium-sodium niobate-based piezoelectric ceramic and a preparation method thereof, the chemical structure of the potassium-sodium niobate-based piezoelectric ceramic is as follows: (1-alpha-beta) Lix (Na1 / 2K1 / 2) 1-xNb1-y (W1 / 2Mn1 / 2) yO3-alpha (Ln2-zSrz) CuO4-beta Bi2O3, Ln is a lanthanide rare earth element; 0 < x < = 0.1, 0 < y < = 0.1, and 0 < z < = 0.5; 0 < alpha < = 0.05, 0 < beta < = 0.05, and the potassium-sodium niobate-based piezoelectric ceramic prepared by the method has excellent piezoelectric properties and has wide application prospects in the fields of transduction, filtering, ultrasonic detection and the like.

The application belongs to the field of functional material preparation, and particularly relates to a Na and Ta co-doped potassium boron niobate antiferroelectric crystal material and a preparation and processing method thereof. 3‑x Na x Nb 3‑y Ta y B2O 12 , wherein x=0.05-0.45, y=0.05-0.5, the Na and Ta co-doped potassium boron niobate antiferroelectric crystal material has a dielectric coefficient increased from 9.85K to 11K at the time of gamma to beta phase transition, and Pmax is increased to 3 times of the original value; through optimization of crystal growth and processing technology, cleavage of the potassium boron niobate antiferroelectric crystal is obviously improved, and no obvious cleavage phenomenon occurs at a temperature of 600 DEG C.

The invention belongs to the technical field of lead-free piezoelectric crystal materials, and particularly relates to a BaMnO2 doped potassium sodium niobate-based single crystal, which has the chemical general formula of (1-x) [(1-y) (K0. 5Na0. 5Nb) O3-yBiFeO3]-xBaMnO2, the invention also discloses a preparation method of the BaMnO2 doped potassium sodium niobate-based single crystal, and the preparation method specifically comprises the following steps: taking Na2CO3, K2CO3, Nb2O5, MnO2, Bi2O3, BaCO3 and Fe2O3 as raw materials, adopting an improved seed-free crystal solid phase growth method, and carrying out primary refining ball milling, pre-sintering, secondary refining ball milling and sintering to obtain the BaMnO2 doped potassium sodium niobate-based single crystal. The BaMnO2 doped potassium sodium niobate-based single crystal provided by the invention has the advantages of high integrity, large size and excellent piezoelectric property.