27results about "From melt solutions" patented technology

The application provides a fluorinated guanidinium borate nonlinear optical crystal and a preparation method and application thereof. The chemical formula of the crystal is [C(NH2)3]B6O9F, the molecular weight is 287.95, the crystal belongs to an orthorhombic system, the space group is Pnma, Pna 21, the cell parameter is a=7.8420(11) Å, b=15.1862(19) Å, c=8.5762(9) Å, α =90°, β =90°, γ =90°, the unit cell volume is 1021.3(2) ų, the crystal is grown by a high-temperature solution method or a flux method, the frequency doubling effect of the crystal is 0.4 times of that of KH2PO4 (KDP), the ultraviolet cutoff edge is 190 nm, the birefringence is large, the birefringence is 0.133 @ 1064 nm, and the deep ultraviolet phase matching capability is deep, the shortest matching wavelength is 196 nm, and the crystal can be applied to deep ultraviolet nonlinear optical crystals in a full solid-state laser.

The application belongs to the technical field of crystal growth, and particularly relates to a SiC single crystal growth method by means of a dissolving agent. The method comprises the following steps: mixing high-purity silicon, metal chromium and metal cobalt, placing the mixture in a graphite crucible or a SiC crucible, heating and smelting under an inert atmosphere or a hydrogen-containing mixed atmosphere, forming a Si-Cr-Co alloy, controlling the Cr content in the alloy to be less than or equal to 60 at.%, the Co content in the alloy to be less than or equal to 20 at.%, and the balance being Si, continuously increasing the temperature to not less than 1800 DEG C, dissolving carbon in the alloy to obtain a Si-Cr-Co-C melt saturated with SiC and carbon, and then growing a SiC single crystal in the melt by means of a top-seed solution growth method or a crucible lowering method. The application introduces cobalt to cooperate with chromium, thereby improving the carbon solubility, inhibiting the aggregation of crystal surface steps, and reducing the doping concentration of the dissolving agent elements in the crystal.

The present application relates to the technical field of cold storage. Specifically disclosed are a cold storage material, and a preparation method therefor and the use thereof. The cold storage material comprises a Gd2O2Se crystal. The cold storage material in the present application comprises the Gd2O2Se crystal, and the Gd2O2Se crystal has a phase transformation near 6.22 K, a relatively large specific heat in a temperature range of 1-10 K, and an obvious magnetothermal effect and can be used as a cold storage material at a liquid helium temperature.

This invention relates to a series of alkali metal rare earth chalcogenides and a series of alkali metal rare earth chalcogenide nonlinear optical crystals, their preparation methods, and their applications. The general chemical formula for both the series of halides and the nonlinear optical crystals is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, all belong to the hexagonal crystal system with space group and cell parameter Z = 1. This series of halides is synthesized using a high-temperature solid-state method, while this series of nonlinear optical crystals is grown using a high-temperature solution method or the Bridgman process. This material can be used to manufacture second harmonic generators, up- and down-frequency converters, optical parametric oscillators, etc.

The application relates to a compound arsenic-silicon-gallium-strontium and an infrared nonlinear optical crystal of arsenic-silicon-gallium-strontium, a preparation method and application, the compound has a molecular formula of SrGa3Si4As 11 , a molecular weight of 1233.26 g / mol, an asymmetric center, and is crystallized in a hexagonal crystal system P , a 63 space group, a cell parameter of a=b=9.2604(3) A, c=11.6484(5) A, Z=2, and V=865.08(7) A 3 , and is prepared into a crystal by using a high-temperature melt method, a chemical vapor phase transmission method or a flux method. The crystal has strong laser damage resistance, large nonlinear optical effect, wide infrared transmission range, and simultaneously has the advantages of large hardness, good mechanical property, not easy to break and deliquesce, easy to process and store and the like, and can be used for manufacturing infrared nonlinear optical devices.

A method for growing a periodically polarized nonlinear crystal may include placing a seed crystal in a melt to form a seed crystal melt mixture, the seed crystal comprising at least one of strontium tetraborate (SBO) or lithium triborate (LBO), and the melt comprising at least one of a mixture of Sr, B, and O or a mixture of Li, B, and O. The method may further include heating the seed crystal melt mixture to a predetermined temperature until a periodically polarized nonlinear crystal is formed.

The present invention provides a method for preparing 3C-SiC single crystals, comprising the steps of: (1) fixing a SiC seed crystal to a graphite seed crystal holder, and then fixing the graphite seed crystal holder to a graphite lifting rod; (2) placing a flux containing Si and Al in a graphite crucible; (3) then loading the graphite crucible and the graphite lifting rod into a growth furnace; (4) vacuumizing the growth furnace, and then introducing a gas to control the gas pressure in the growth furnace and the crystal form of 3C-SiC; (5) heating the graphite crucible until the flux is completely molten to form a melt, and reaches the growth temperature of SiC, (6) pushing down the graphite lifting rod to make the SiC seed crystals contact with the melt, thereby growing 3C-SiC single crystals; wherein the flux further contains a 3d-transition metal with a melting point lower than the growth temperature of SiC. The method of the present invention can achieve the growth of high-quality, large-size (such as 2-6 inches), low-defect, single-crystal form, and uniformly doped n-type, p-type and semi-insulating 3C-SiC single crystals.

The application provides a seed crystal protection device and an application method thereof, and relates to the technical field of single crystal growth. The seed crystal protection device comprises a device main body and a matching structure. The device main body is provided with a first accommodating cavity, and one side of the first accommodating cavity is provided with an opening. The matching structure is connected with the device main body. The matching structure has a connected state and a separated state. In the connected state, the matching structure is suitable for being connected with a connecting device, so that the seed crystal assembled in the connecting device is accommodated in the first accommodating cavity through the opening. The first accommodating cavity can wrap the seed crystal and reduce the probability of contamination of the seed crystal. Meanwhile, in the separated state, the matching structure is suitable for being separated from the connecting device, and the device main body can fall into a reaction container located on the side of the seed crystal away from the connecting device. Therefore, the wrapping restriction on the seed crystal can be removed, and the seed crystal can normally grow crystals under the action of the melt in the reaction container.

The application relates to a method for preparing a compound crystal by melt migration under high gravity, and relates to the field of semiconductor preparation, and the method comprises the following steps: placing a compound semiconductor polycrystal with a molecular formula of AxBy, an element of A and a seed crystal in a crucible in sequence and closely contacting each other, horizontally placing the crucible on a centrifugal rotating device, heating the crucible to T0 (800 DEG C < T0 < T m , starting the centrifugal rotating device, and making a centrifugal force G greater than 100g; after the centrifugal force is applied, the elements A and B in the melt move to both sides of the melt pool, the polycrystal is dissolved, and the seed crystal starts to grow into a single crystal; with the polycrystal being continuously dissolved and the single crystal being continuously grown, the melt migrates to the polycrystal direction, and single crystal preparation is realized. By using the method, single crystal can be grown at low temperature, the critical shear stress of a growth interface is improved, and dislocation density is reduced. Meanwhile, the requirement of a pressure equipment and growth conditions are reduced, and a crystal which cannot be prepared by a melt method can be efficiently grown by the melt method.

The present invention provides a method for manufacturing a group III nitride semiconductor that can improve crystallinity. [Solution] A method for manufacturing a group III nitride semiconductor, comprising: an alkali metal coating step of covering the surface 11a of a solid alkali metal 11 with a group III metal 12; a mixed melt generation step of melting the alkali metal 11 coated with the group III metal 12 together with carbon 13 to produce a mixed melt; and a crystal growth step of immersing a seed substrate in the mixed melt under a nitrogen-containing atmosphere to grow a group III nitride semiconductor on the seed substrate.

The application relates to a method for growing large-size ZnIn2Te4 single crystals by a flux method, the method is characterized in that: an excessive Te is used as a flux to reduce the melting point of reactants, specific proportions of Zn sources, In sources and Te sources are weighed and mixed as raw materials, the raw materials are made to react and grow crystals by setting a suitable temperature gradient, and finally, the excessive flux Te is centrifuged to obtain ZnIn2Te4 single crystals with low defects and high quality. The ZnIn2Te4 single crystals prepared by the method have a non-central symmetric structure, belong to a tetragonal system, and have a space group I-4, and have the characteristics of large size and high quality, and can provide materials for intrinsic property research and development of photoelectric devices, thermoelectric devices and other functional devices.

This invention discloses an intrinsic superlattice single-crystal material and its preparation method, belonging to the field of single-crystal growth technology. The single crystal has the chemical formula BaLaMnSb4, and its crystal structure consists of alternating stacks of BaMnSb2 and LaSb2 layers in an intrinsic superlattice configuration perpendicular to the layer direction. This invention utilizes a self-fluxing method to grow a novel magnetic topological material, BaLaMnSb4, with an intrinsic superlattice. This single crystal has a structure composed of BaMnSb2 and LaSb2 layers... ­2 The alternating intrinsic superlattice structure, with its high single-crystal quality, few defects, and large size, is an ideal research platform for magnetic topological materials.

The disclosure provides a fluorinated guanidinium borate compound and a preparation method and application thereof, and belongs to the technical field of crystal materials and the technical field of optics. The chemical formula of the fluorinated guanidinium borate compound is (C(NH2)3)2B2OF6.

This invention relates to the compounds strontium lanthanum chloroborate and barium lanthanum chloroborate, as well as nonlinear optical crystals of strontium lanthanum chloroborate and barium lanthanum chloroborate, their preparation methods, and their uses. The general chemical formula for both the compounds and crystals is A3La4B3O. 13 Cl, where A = Sr, Ba, space group P63, belongs to the hexagonal crystal system, and cell parameter Z = 2. The compounds lanthanum strontium chloroborate and lanthanum barium chloroborate are synthesized by a solid-state reaction method. The nonlinear optical crystals of lanthanum strontium chloroborate and lanthanum barium chloroborate are grown using a high-temperature melt method. This material can be used to manufacture second harmonic generators, up-down frequency converters, optical parametric oscillators, etc.

The invention belongs to the technical field of single crystal materials, and particularly relates to a SrxBi2Se3 topological superconducting single crystal material and a space preparation method and application thereof. The size of the SrxBi2Se3 topological superconducting single crystal material is larger than or equal to 10 mm * 8 mm * 0.5 mm, the superconducting transition temperature of the SrxBi2Se3 topological superconducting single crystal material is larger than or equal to 3 K, and the doping amount of Sr in the SrxBi2Se3 topological superconducting single crystal material is larger than or equal to 70% of the actual using amount of Sr. Wherein x is more than 0 and less than or equal to 0.3. The preparation method of the SrxBi2Se3 topological superconducting single crystal material has the beneficial effects that the SrxBi2Se3 topological superconducting single crystal material is prepared in a microgravity environment, ideal conditions without convection and sedimentation are provided, solute segregation can be effectively inhibited, uniform nucleation and growth are promoted, and proper conditions are provided for growth of Sr-doped Bi2Se3 single crystals. The microgravity environment is based on a space station experiment platform, and efficient and high-quality space preparation of the SrxBi2Se3 single crystal is achieved.

A W-Nb series W-based rare solid solution alloy single crystal and a preparation method thereof belong to the field of new material research and preparation, and have a chemical composition of W 100‑x Nb x wherein x is an atomic percentage, and the value of x is 0.1 to 5.The preparation method uses a flaky single crystal pure tungsten with a specific crystal orientation as a seed crystal, and through precisely controlled non-consumable arc melting parameters, a target solid solution alloy single crystal sample with the same orientation as the seed crystal is prepared on the surface of the flaky seed crystal, and then annealing is performed at a high temperature to obtain a W-Nb series tungsten-based rare solid solution single crystal with good composition uniformity, controllable orientation and high structural integrity.The W-Nb series tungsten-based rare solid solution alloy single crystal with accurate composition, good uniformity, high controllability of orientation and high perfection of structure is successfully prepared, a new path is provided for the research and preparation of tungsten and its alloy single crystal, the preparation method has a clear process path, strong parameter adjustability, and is simple and easy to implement, and has good applicability and promotional value.

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.

This invention discloses a high-alumina-doped single-crystal cathode material and its preparation method, belonging to the technical field of lithium-ion battery cathode materials. To address the problem in high-alumina-doped or multi-element-doped cathode materials that the high content of inert dopants leads to a sluggish lithium intercalation thermodynamic process and dopant segregation, easily forming numerous two-dimensional defects such as grain boundaries, twin boundaries, and phase boundaries, this invention prepares a high-alumina-doped Co-containing precursor, combines it with a lithium source and flux for a first-stage solid-state sintering to obtain the cathode material matrix, and then mixes it with a coating additive for a second-stage solid-state sintering to obtain the high-alumina-doped single-crystal cathode material. This invention can significantly improve the grain boundary structure of the cathode material, increase the degree of single crystallization and structural stability, and is suitable for high-voltage lithium-ion batteries.

The application provides a preparation method and application of a series of tellurium niobate compounds and crystals thereof, and the chemical general formula of the crystals is A2Nb2Te4O 15 , wherein A is selected from Ca, Mg, Sr or Ba. The molecular formula of the series of tellurium niobate compounds is Mg2Nb2Te4O 15 , Ca2Nb2Te4O 15 , Sr2Nb2Te4O 15 , Ba2Nb2Te4O 15 , respectively. The crystals are crystallized in an orthorhombic system, and the space group is Pma 2. The application successfully synthesizes a series of novel compounds with non-centrosymmetric structures based on a functional unit complex method. Experimental measurement shows that the crystals have high powder frequency doubling effect, are superior to a commercial benchmark material KTP, have an ultraviolet absorption cutoff edge shorter than 300 nm, an infrared cutoff edge wider than 6 mm, and moderate birefringence, and are expected to realize wide-band and high-power laser output. In the preparation method, a flux method is used to obtain single crystals with excellent optical quality.

The application belongs to the technical field of lithium ion battery materials, and discloses a high-nickel single-crystal positive electrode material with a cationic mixed arrangement degree of 1.9% to 3.6% and including single-crystal particles with a sheet-like morphology. A hydroxide precursor material of the high-nickel single-crystal positive electrode material is mixed with a lithium salt and a molten salt to obtain a mixture; the molten salt at least includes lithium nitrate; the mixture is subjected to two-stage sintering in an oxygen atmosphere, first sintering at 400 to 500 DEG C, and then sintering after being heated to 650 to 750 DEG C to obtain a black powder; the black powder is washed with water, dried, mixed with a lithium salt, and then sintered at 500 to 600 DEG C to obtain the high-nickel single-crystal positive electrode material. The high-nickel single-crystal positive electrode material including single-crystal particles with a sheet-like morphology has a low cationic mixed arrangement degree, which is beneficial to improving the reversible capacity and cycle stability of a lithium ion battery. The high-nickel single-crystal positive electrode material with a low cationic mixed arrangement degree is prepared at a low sintering temperature, and the preparation method is simple, reliable, easy to operate, and beneficial to reducing the industrial production cost.

A method for preparing a molten salt assisted copper-based coating superconductor and its application. By selecting a copper-based oxide superconducting material and a carrier and designing a molten salt component, an external reaction atmosphere and a heat treatment condition, the oxide precursor prepared according to the cation stoichiometry is mixed with a low-melting-point molten salt and placed on the surface of the carrier, and the precursor is dissolved and migrated in the molten salt under the condition of controlled atmosphere and temperature, and then deposited and crystallized on the surface of the carrier to form a superconducting coating in a non-uniform nucleation manner; after the reaction, the residual molten salt is removed by washing to obtain a coated superconductor, and the superconducting powder generated in the reaction is recovered and the molten salt is recycled for recycling. The present application can realize the controllable preparation of planar or curved coating in the thickness range of nanometer to hundred microns, and the multi-morphology coating structure of strip, fiber, porous body and microsphere array, and has good process window and coverage, and can be recycled to reduce cost. The obtained coating and powder can be used in the fields of superconducting wires and coated conductors, high-field magnets, microwave devices and quantum devices.

A lead decahydroxydecaborate dihydroxy monoborate monohydrate nonlinear optical crystal, and its preparation method and application are provided. The chemical formula of this crystal is Pb2B10O16(OH)2·B(OH)3·H2O, its molecular weight is 892.35, and it belongs to the monoclinic crystal system, space group P21. The crystal is grown using a hydrothermal method in a closed system, or using a room temperature solution method in an open system.

This invention provides a method for growing group III nitride single crystals with high crystal quality using an MPS substrate. [Solution] A method for growing a group III nitride single crystal, comprising: an alkali metal melt preparation step S1 of preparing an alkali metal melt from which oxygen atoms have been removed; a seed substrate preparation step S2 of preparing a seed substrate on which a plurality of seed crystals made of a group III nitride semiconductor are formed in a dot pattern; an initial nucleation step S3 of forming initial nuclei on the seed crystals by bringing a mixture of the alkali metal melt and a melt of a group III metal into contact with the surface of the seed crystals in a nitrogen-containing atmosphere; and a crystal growth step S4 of growing a group III nitride single crystal from the initial nuclei by bringing the mixture into contact with the initial nuclei in a nitrogen-containing atmosphere.

The present application provides a high-nickel single crystal positive electrode material and a production method, a positive electrode sheet, a secondary battery and an electric device thereof. The chemical formula of the high-nickel single crystal positive electrode material is Li1+δNixMyQ1-x-yO2+εAαRβXγ, wherein 0.8≤x<1, 0<y≤0.2, 0≤δ≤0.15, 0<ε≤0.2, 0<α≤0.04, 0<β≤0.04, 0≤γ≤0.04, the M element and the Q element each independently include one or more of Mn, Co, Al, Ta, Ti, Nb, Ge, Y, Nb, W, Zr, Ce, Ca, Sr, Sc, V, Cr and Mo; the A element includes one or more of Mg, Ca, Sr, Ba, Ti, Zr, V, Nb, Ta, Mo, W, La, Ce, Sc and Cr; the R element includes one or more of B and P; the X element includes one or more of Na, K, Mn, Mg, Ca, Sr and Al; a molar ratio of surface Ni3+ of the high-nickel single crystal positive electrode material is 38%-55%, and a molar ratio of surface lattice oxygen is 7%-15%. The structural defects of the material are significantly reduced, thereby increasing its specific capacity and improving its cycle performance.