205 results about "Polycrystalline material" patented technology

The invention provides a modified lithium-rich manganese-based positive electrode material, a preparation method thereof and a lithium ion battery, and relates to the technical field of new energy. According to the modified lithium-rich manganese-based positive electrode material disclosed by the invention, multi-element point position doping is carried out on a base material to enhance the structural stability of a polycrystalline material, inhibit transition metal ion migration and interlayer dislocation, improve the internal lattice strength and manufacture a stable base material core; the heterostructure layer can greatly improve the surface structure phase change and transition metal dissolution of the material surface under high voltage, the stability of the surface of the matrix material is improved, and the rate capability of the material can be improved by the in-situ generated three-dimensional ion channel; the coating layer can effectively reduce side reaction of a solid-liquid interface, improve dissolution of metal ions on the surface and improve the cycle performance of the material; in a word, the internal structure and the surface of the material are effectively modified mainly through three means of doping, interface structure design and coating, the multiplying power of the material can be greatly improved, and the long-term service life of the material can be greatly prolonged.

Disclosed herein are methods for setting the radiation sensitivity and operational temperature range of ion-conducting polycrystalline radiation detectors. Disclosed herein are material fabrication methods for setting the ion-conducting polycrystalline microstructure and the grain boundary ion blocking characteristics in ion-conducting polycrystalline materials. The methods may include introducing a selected precursor element into the grain boundaries of the ion-conducting polycrystalline material. These methods may allow for the device detection threshold, dynamic range, and / or operational temperature range to be adjusted for ion-conducting polycrystalline radiation detectors. The methods disclosed herein allow for the design of high-sensitivity and high-performance radiation detectors that are low cost, non-toxic, environmentally robust, scalable, and able to operate in harsh environments (e.g., high temperature, high humidity, pressure, and / or corrosive).

New high entropy ceramics comprising rare earth oxides are disclosed. The new high entropy ceramic materials generally contain from five to ten different rare earth oxides with each of the rare earth oxides comprising a different rare earth element. The new ceramic materials may be substantially single-phase, polycrystalline materials. The new ceramic materials may realize improved properties, such as plasma etch resistance, among others.

The invention discloses a laser single crystal optical fiber doped with ions in a gradient manner and a preparation method of the laser single crystal optical fiber, when the single crystal optical fiber is prepared, firstly, raw materials with different doping concentrations are uniformly mixed respectively, then the raw materials are pressed into sheets respectively, the sheets are pressed for the second time to enhance compactness, then the pressed sheets are sintered to obtain a polycrystal material, and the polycrystal material is sintered to obtain the laser single crystal optical fiber doped with ions in a gradient manner. The preparation method comprises the following steps: respectively grinding a polycrystalline material until the polycrystalline material passes through a 400-mesh sieve, filling polycrystalline material powder into a strip balloon in a gradient segmentation manner, compacting and sealing, pressing and sintering to obtain a ceramic material rod, cutting the ceramic material rod into a ceramic square rod, and performing seeding growth by adopting a laser heating base method and taking the ceramic square rod as a source material rod to obtain the gradient ion-doped laser single crystal optical fiber. Compared with the prior art that the laser single crystal fiber doped with the ions in the gradient mode is prepared through a welding process, the method is low in process difficulty, welding interface diameter fluctuation does not need to be accurately controlled, the yield is high, the procedure is simple, and the production efficiency is high.

The invention discloses a polycrystalline material microstructure crack evolution simulation and mechanical property prediction method and system. The method comprises the following steps: establishing a voronoi geometric model of a polycrystalline material containing grain characteristics and microstructure defect characteristics; carrying out spatial distribution modeling on the mechanical property parameters of the polycrystalline material based on a probability statistics theory; importing the voronoi geometric model of the polycrystalline material into a multi-physics field simulation software platform, establishing a complete simulation geometric model for crack prediction based on a phase field fracture theory, and performing phase field solution; setting corresponding material parameters according to the material attributes; and setting corresponding boundary conditions in simulation software to simulate a four-point bending experiment, solving a phase field fracture control equation by utilizing a finite element algorithm, capturing a change rule of a crack propagation path, and recording key mechanical data. According to the method, the polycrystalline Voronoi model is constructed, spatial distribution modeling is carried out on the mechanical parameters of the material in combination with the probability statistics theory, and the non-uniform characteristic of the actual material can be reflected more truly.

The invention relates to the technical field of preparation of single crystal materials, in particular to a low-cost lead-free piezoelectric single crystal with high piezoelectric response and a preparation method, the lead-free piezoelectric single crystal is of a lead-free perovskite structure, the chemical general formula of the lead-free piezoelectric single crystal is xBi < 0.5 > Na < 0.5 > TiO < 3-y > Bi < 0.5 > K < 0.5 > TiO < 3-(1-x-y) Bi < 0.5 > Li < 0.5 > TiO < 3 >, x is equal to 0-1, y is equal to 0-0.2, and x is equal to 0-1. The preparation method comprises synthesis of a multi-component lead-free precursor polycrystalline material, interface construction of a seed crystal and a polycrystalline substrate, and a high-temperature solid-phase epitaxial growth process. The components and various key process parameters of the material involved in the invention are finely controlled, the process window in the preparation process is narrow, reverse analysis is not easy to occur, and the preparation method has a remarkable technical barrier and is suitable for industrial popularization as a key preparation technology of the high-performance lead-free piezoelectric single crystal material.

The invention discloses a preparation method of a lithium cobalt oxide positive electrode material, the lithium cobalt oxide positive electrode material and a lithium battery, and relates to the technical field of lithium ion batteries. The method comprises the following steps: firstly, preparing a polycrystalline lithium cobalt oxide defective product and a single-crystal lithium cobalt oxide defective product, and respectively introducing doping elements in a first additive and a second additive into the polycrystalline lithium cobalt oxide defective product and the single-crystal lithium cobalt oxide defective product; a polycrystalline lithium cobalt oxide defective product, a third additive and a fourth additive are mixed and sintered, a sintering aid (the third additive contains a doping element M1) and a high-valence transition metal compound (the fourth additive contains a doping element M2) are matched, a high-melting-point Li-Co-M1-M2 phase is generated at the grain boundary, the grain boundary binding energy is improved, and therefore the compressive strength of the polycrystalline material is improved. After the grain boundary optimized lithium cobalt oxide defective product and the monocrystal lithium cobalt oxide defective product are graded, the lithium cobalt oxide positive electrode material with high compaction density can be obtained, and meanwhile, the positive electrode material can give consideration to rate performance and cycle performance.

The invention discloses a twin crystal nucleation position and variant selection prediction method based on machine learning, and belongs to the crossing field of material science and machine learning. The method comprises the following steps: acquiring microscopic structure data of a deformation material through electron back scattering diffraction, and constructing a multi-dimensional data set containing crystal grain parameters, crystal boundary parameters and deformation mechanism parameters by taking crystal grains and a certain crystal boundary combination as an analysis unit; and then modeling and predicting the twin crystal nucleation position and variant selection respectively by adopting a hierarchical machine learning modeling strategy. According to the method, the twinning behavior in the polycrystalline material can be efficiently and accurately predicted, and theoretical support and a technical path are provided for high-performance metal material design and plastic deformation mechanism research.

A latent heat storage includes a ceramic part, formed of a polycrystalline material, and including a closed space famed therein, and a metal part provided inside the closed space, and including copper.

The invention relates to a sulfur-antimony-lanthanum-barium compound, a sulfur-antimony-lanthanum-barium mid-far infrared birefringent optical crystal and a preparation method and application thereof, relates to a mid-far infrared birefringent crystal and a preparation method and application thereof, and aims to solve the problem of low birefringence of the existing mid-far infrared crystal, the sulfur-antimony-lanthanum-barium compound has the chemical formula of Ba2La2Sb4S10 (S2) and the molecular weight of 1424.22, is crystallized in a monoclinic system, and has the molecular weight of 294nm. The space group is P21 / c, and the cell parameters are as follows: a = 8.6373 (5), b = 14.7336 (9), c = 15.9161 (9), alpha = gamma = 90 degrees, and beta = 92.661 (2) degrees. Preparing a compound or a polycrystal material by using a high-temperature solution or a solid-phase method; a polycrystalline material is used for growing a single crystal, the birefringence of the single crystal is 0.53 at the position of 1064 nm, the single crystal has large birefringence within the range of 1-14 microns, and the single crystal is used in an optical isolator, a circulator, a beam shifter, an optical polarizer or an optical modulator.

The embodiment of the invention discloses a system and method for rapidly representing a grain boundary network by using a series of transmission electron microscope dark field images, and belongs to the field of polycrystalline material microstructure characterization, and the method comprises the following steps: collecting series of dark field images at different positions on a plurality of diffraction rings; correcting drifting of the series of dark field images; for any position in the dark field image, taking the intensity change of the series of dark field images at the same pixel as the feature of the pixel, and calculating the data similarity of the pixel and the features corresponding to a plurality of adjacent pixels; and synthesizing and visualizing the similarity between any pixel and a plurality of adjacent pixels to obtain the form of the crystal boundary network. The method for rapidly characterizing the grain boundary network by using the series of transmission electron microscope dark field images provided by the embodiment of the invention has the advantages of high spatial resolution, insensitivity to crystal defects, small irradiation damage and capability of rapidly and accurately obtaining the grain boundary network, and can support further enrichment of material characterization technologies and provide technical support for development of crystal materials.

New substantially single-phase polycrystalline materials are disclosed. The new substantially single-phase polycrystalline materials generally include from 0.01-20 mol. % zirconia, at least 80 mol. % of one or more rare earth oxides (REO), and 40 to 7000 ppm aluminum by weight, wherein the substantially single-phase polycrystalline material comprises at least 95 wt. % of a solid-solution of REO-zirconia as measured by x-ray diffraction. The new substantially single-phase polycrystalline materials may realize a high density, such as a density of at least 95% of theoretical density, or higher. The new substantially single-phase polycrystalline materials may be in the form of a semiconductor component, including those suited for use in a plasma chamber environment.

The invention provides a solar cell and a manufacturing method thereof, and relates to the field of solar cells. The invention aims to solve the problem that the passivation influence of laser on a textured P region is relatively large. The manufacturing method comprises the steps that a semiconductor substrate of a first conduction type is provided, the back face of the semiconductor substrate comprises first parts and second parts which are alternately arranged, and third parts located between the adjacent first parts and second parts; the first part comprises a first sub-part and a second sub-part, and the second sub-part is adjacent to the third part; forming a diffusion layer and a first mask layer; forming a tunneling passivation layer; forming a doped polycrystalline material layer and a second mask layer; removing the second mask layer on the third part and the second sub-part by utilizing first laser etching; and exposing the surface of the semiconductor substrate corresponding to the third part and the second sub-part by adopting a wet etching mode to form a step-shaped spacing structure. The manufacturing method has no adverse effect on passivation of the area where the emitter is located.

The invention relates to the technical field of grain size modeling, in particular to a pseudo-random high-fidelity modeling method for a multiphase polycrystalline material grain size microstructure, which comprises the following steps of: counting the size distribution, orientation distribution and orientation difference distribution among grains of each phase; carrying out statistics on size distribution, quantity proportion and orientation difference distribution between the categories of each category; constructing a geometric boundary; generating a core crystal grain reference point in the geometric boundary, arranging other crystal grain reference points in the residual space, and determining a growth weight according to a size relationship between adjacent crystal grains; and generating a grain size microstructure geometric model. According to the method, the weighted Voronoi method is introduced, and the weight is determined according to the spatial position relationship of the reference points and the expected growth size (target grain size), so that the growth rates of different grains in different directions are different, and the competitive growth behavior of the grains in an actual material is truly reproduced; the problem that in existing Voronoi modeling, the growth speed of crystal grains in all directions is uniform is solved, and the obtained microstructure model is beneficial for improving the simulation precision of the real mechanical behavior of the material.

A SAW resonator with reduced spurious modes is provided. The resonator comprises a (111) silicon carrier substrate (CS), an electrode structure (ES) and a piezoelectric layer (PIL). The carrier substrate has a crystal orientation with the Euler angles (−45°±10°; −54°±10°; 60°±30°) and the piezoelectric layer comprises LiTaO3 and has a crystal orientation with the Euler angles (0°; 56°±8°; 0°). There may be intermediate layers (IL1, IL2) of SiO2 and amorphous or polycrystalline materials. In addition a silicon nitride layer is provided as passivation (PAL). Electrodes are made of aluminum. Thicknesses of all layers are selected in particular ranges to optimize SAW behaviour.

A particulate cathode active material comprising (A) a base material according to the general formula Li1 + xTM1-xO2, where TM is a combination of Ni with at least one of Mn, Co and Al, and optionally at least another metal selected from the group consisting of Mg, Ti, Zr, Nb, Ta and W, and x is in the range of 0 to 0.2, and (B) crystallites of one or more cobalt compounds, where at least some of the cobalt is in the oxidation state of + III, where the base material (A) is a polycrystalline material, where x is greater than 0 and less than 1. The secondary particles of which consist of primary particles, and crystallites (B) of a cobalt compound are coated on the outer surfaces of these secondary particles, and one or more cobalt compounds are enriched at the surfaces of the primary particles in the voids between adjacent primary particles, and wherein 90% to 99.5% of the secondary particles exhibit such cobalt compound enrichment, all the detection results are determined through EDX and SEM / TEM imaging.

The present disclosure relates to a layered seed for growing a volume mono crystal by gas phase growth in a direction of growth (Y) in a crucible (1200). The layered seed comprises a monocrystalline growing layer (110) with a growing surface (112) for growing the volume mono crystal and an opposing heat spreader facing surface (114) for coupling the growing layer (110) to a heat spreader layer (140). The layered seed further comprises the heat spreader layer (140) with a growing layer facing surface (144) for coupling to the heat spreader facing surface (114) and an opposing mounting surface (142) for mounting the heat spreader layer (140) to the crucible (1200), wherein the heat spreader layer (140) comprises a polycrystalline material having thermally coupled grains (146) that are piled in the direction of growth (Y), the piled grains (146) for equalizing hot spots of the crucible thermally coupled to the mounting surface (142).

The invention discloses a diamond polycrystalline substrate with high heat conductivity and good light transmission and application, and belongs to the technical field of diamond polycrystalline materials. The heat conductivity of the diamond polycrystalline substrate at any position is greater than or equal to 1560 W / (m.K); and the light transmittance at any position is greater than or equal to 48%. According to the diamond polycrystalline substrate, the heat conductivity is improved, meanwhile, amorphous carbon can be prevented from being formed, black spots do not exist in the diamond polycrystalline substrate, and therefore the heat conductivity and the light transmittance are both improved.

A sintered cathode includes a first surface, a second surface opposite the first surface, a sintered polycrystalline material, a thickness greater than or equal to 5 µm, and a porosity less than 35%. The polycrystalline material includes a plurality of crystal grains having a layered rock-salt structure. A crystal direction of the plurality of crystal grains is random relative to a first surface and a second surface. A method of forming a sintered cathode includes mixing lithium-containing particles and cobalt-containing particles to form a LCO precursor powder including a LT-LCO phase, dispersing the LCO precursor powder in a binder and a solvent to form a slurry, tape casting the slurry to form a green tape including the LT-LCO, and sintering the green tape to form a sintered cathode including a HT-LCO phase and a random grain texture.

A multilayer ceramic electronic component is equipped with a ceramic component and an external electrode. Said ceramic body has a plurality of internal electrodes that are stacked in the direction of a first axis, and an end surface that is perpendicular to a second axis that is orthogonal to the first axis, and from which said plurality of internal electrodes are drawn. Said external electrode includes a base layer that covers said end surface and is connected to said plurality of internal electrodes. Said plurality of internal electrodes and said base layer are made of a polycrystalline material mainly composed of copper. The average crystal grain size of the base layer described above is 1.2 times or more that of the plurality of internal electrodes described above.

The invention relates to a method for manufacturing a composite structure comprising a thin layer of monocrystalline material arranged on a carrier substrate made of polycrystalline material, the manufacturing method comprising the following steps: a) providing a raw disk made of polycrystalline material having two faces; b) measuring at least one curvature parameter of the raw disk so as to define a first face with a convex profile and a second face with a concave profile, and selecting the first face to correspond to a front face of the carrier substrate at the end of step c); c) preparing the carrier substrate from the raw disk, involving mechanical and / or chemical treatment of the faces of the raw disk, the carrier substrate having a front face and a rear face corresponding to the first face and the second face of the raw disk, respectively; d) transferring the thin layer onto the front face of the carrier substrate in order to obtain the composite structure.

The invention relates to a device for non-destructive testing of mechanical parts made of polycrystalline material, said device comprising: - an ultrasonic probe (1) comprising a two-dimensional array of transducers capable of transmitting and receiving signals at different excitation angles, and - a processing module (2) adapted to control the transmission and reception of the transducers, to process the signals received by the transducers so as to express the signals received by the ultrasonic probe in two plane wave planes constituted by the transmission and reception wave vectors of the probe, and to derive therefrom information representative of the three-dimensional orientation of the fibrous structure of the mechanical part.

The invention discloses a synthesis method of a selenium and sulfide infrared optical crystal, which comprises the following steps: weighing elementary substance raw materials of each element according to the stoichiometric ratio of the selenium and sulfide infrared optical crystal, additionally weighing elementary substance selenium or elementary substance sulfur with the molar ratio of 2-5%, and then filling each elementary substance raw material into a crucible; vacuumizing the crucible filled with the simple substance raw material, and sealing by using oxyhydrogen flame; putting the sealed crucible into another quartz crucible, vacuumizing, and sealing by adopting oxyhydrogen flame; putting the double-layer crucible into a double-temperature-zone tubular furnace, then respectively heating a high-temperature zone and a low-temperature zone of the double-temperature-zone tubular furnace, and after the low-temperature zone is heated to a reaction temperature in a gradient manner, keeping the temperature for 5-10 hours; then mechanically oscillating the double-temperature-zone tubular furnace for 3-5 times, and then keeping the temperature for 5-10 hours; after the reaction is finished, carrying out temperature oscillation for 2-3 times; and finally, cooling the double-temperature-zone tubular furnace to room temperature. Cracking and explosion of the crucible can be effectively avoided, deviation of the stoichiometric ratio can be effectively prevented, and the high-purity polycrystal material is obtained.

A method for two-dimensional mapping of crystal information of a polycrystalline material may include acquiring a diffraction pattern acquired by scanning an electron beam to a polycrystalline material, generating a plurality of clusters by applying a clustering algorithm to the acquired diffraction pattern based on unsupervised learning, acquiring crystal information of the polycrystalline material by applying a parallel deep convolutional neural network (DCNN) algorithm to each of the plurality of generated clusters based on supervised learning, and generating a two-dimensional image in which the acquired crystal information is mapped.

The present invention (A) General formula Li 1+x TM 1-x A core material made of O2, wherein TM is a combination of Ni, Al, at least one of Mn and Co, and at least one metal optionally selected from Mg, Zr, Ti, Nb, Ta and W, x is in the range of 0 to 0.2, and at least 80 mol% of TM is nickel. (B) A coating containing at least one boron compound in the oxidized state of (B)+III, Regarding cathode active materials containing, Here, the core material (A) is a polycrystalline material composed of primary particles as secondary particles, and the lattice constant ratio c / a determined by X-ray diffraction and Rietveld refinement is 4.9420 or less. 0.0009 ≤ λ ≤ 0.0024, where λ is the molar ratio of sulfate to TM determined by inductively coupled plasma spectroscopy (ICP), and the sulfate concentration is essentially constant across the secondary particle size.

This application provides a lithium-rich manganese-based cathode material, its preparation method, cathode sheet, and battery. The chemical formula of the lithium-rich manganese-based cathode material includes Li[Li] a Ni x Co y Mn z M d N e ]O 2‑f D f M is a metallic element, and the ionic radius of element M is greater than that of Mn. 4+ The oxidation state of element M is not less than +5; N includes at least one of Ce, Zr, Sn, La, Mg, Ti, Si, Sr, Se, Fe, Cr, V, Ca, Hf, Al, K, and Na; D includes at least one oxyacid anion of P and one oxyacid anion of S; the cathode material is a polycrystalline material, with at least a portion of the oxyacid anions of P and at least a portion of the oxyacid anions of S distributed at the grain boundaries of the primary particles of the cathode material, and at least a portion of M distributed within the lattice of the primary particles of the cathode material. The lithium-rich manganese-based cathode material of this application possesses both high ionic conductivity and low irreversible lattice oxygen loss under high voltage.

The invention discloses a preparation method of in-situ large-size high-density semiconductor-grade high-purity silicon carbide multi-crystal grains, and relates to a preparation method of a high-purity semiconductor-grade silicon carbide polycrystal material. The method aims at solving the technical problems that silicon carbide polycrystalline particles prepared by an existing method are small, secondary crystallization is needed, energy consumption is high, and the yield is low. The method comprises the following steps: preparing precursor resin as a nucleation seed crystal and an adhesive by adopting a non-catalytic suspension polymerization method; 2, preparing a silicon-carbon pre-sintered body; and 3, preparing the in-situ large-size high-purity semiconductor-grade silicon carbide polycrystalline material through a curing process, a self-propagating synergistic carbon thermal reduction reaction process, an in-situ silicon carbide grain growth process and an in-situ silicon carbide grain densification process. The particle size of the prepared silicon carbide multi-crystal grains is 0.8-20mm, the purity reaches 6N, the density reaches 1.6-2.5 g / cm < 3 >, the yield is 85-90%, and the silicon carbide multi-crystal grains can be used in the field of silicon carbide preparation.

The invention provides a crystal growth device and a crystal growth method, and belongs to the technical field of crystal growth. According to the crystal growth method, the seed crystal is fixed to the seed crystal section, the growth crucible is rotated so that the seed crystal can still be located in the seed crystal section, at least part of the polycrystal material falls into the tail section, the polycrystal material falling into the tail section can be fully overheated in a partitioned heating mode, the temperature of the seed crystal located in the seed crystal section is strictly controlled, and the crystal growth efficiency is improved. And the temperature is below the melting point, so that complete melting is avoided. After the polycrystal material is completely molten, the growth crucible is rotated again, the molten polycrystal material falls into the shouldering section and is in contact with the seed crystal, and the polycrystal material close to the position of the seed crystal is subjected to sufficient overheating convection due to sufficient overheating of the polycrystal material, so that welding with the seed crystal is facilitated, and the seeding success rate of preparing large-size single crystals by adopting a seeding method is improved. The crystal growth method provided by the invention is suitable for growth of all types of crystal materials, and can solve the ubiquitous problem of insufficient overheating of polycrystal materials in the existing seeding method.

A method to calculate performance of a magnetic element including a reference bilayer including a ferromagnetic reference layer having a reference magnetization and an antiferromagnetic layer pining the reference magnetization by exchange-bias, the antiferromagnetic layer including a metallic polycrystalline material having a grain volume distribution; the method including: measuring an exchange-bias field (Hex) of the antiferromagnetic layer as a function of temperature; fitting a grain volume distribution function to the measured exchange-bias fields (Hex) to determine parameters characterizing the volume distribution function; calculating a variation in the direction of the reference magnetization as a function of a direction of an exposure magnetic field (H); and calculating the exchange bias field (Hex) for any value of the in-plane exposure field (H).

The invention provides a double-layer crucible. The double-layer crucible comprises an outer circular tube-shaped container, an inner circular tube-shaped container and a T-shaped cylindrical plug, the double-layer structure can solve the problems of raw material loss and proportion imbalance caused in the process of filling the raw materials into the crucible, and the perovskite crystal which can be used for normal-temperature nuclear radiation detection can be industrially prepared by using the Bridgman method in an economic mode. And a vacuum cavity can be provided as a temperature buffer area, so that the thermal disturbance of a crystal growth interface is reduced. The method can also be used for atmosphere regulation and control, and component segregation caused by element volatilization is relieved. The invention also provides a method for preparing a perovskite polycrystal material and a method for preparing a perovskite single crystal.