168 results about "Lattice constant" patented technology

The invention provides a Si-based InGaAs photoelectric detector and a preparation method thereof. The Si-based InGaAs photoelectric detector comprises a Ge transition layer, a GaAs transition layer and a non-doped InP buffer layer, wherein the Ge transition layer, the GaAs transition layer and the non-doped InP buffer layer sequentially grow on the surface of a silicon substrate; the lower doped InP layer, the non-doped InGaAs absorption layer and the upper doped InP layer are sequentially grown on the surface of the non-doped InP buffer layer. The Si-based Ge epitaxial layer, the Ge-based GaAs epitaxial layer and the GaAs-based InP epitaxial layer which are mature in process are sequentially inserted between the Si substrate and the III-V group heteroepitaxial thin film, the crystal structure type difference of direct epitaxial growth of InGaAs on Si is eliminated, the lattice constant mismatch degree is reduced, the defects of the InGaAs epitaxial layer are reduced, the quality is improved, and a high-performance detector is better prepared.

The invention discloses an alloy high-temperature and high-pressure environment simulation method under radiation action based on molecular dynamics, which comprises the following steps: establishing a molecular structure framework of an alloy according to a crystal structure and a lattice constant of the alloy, and setting initial parameters to construct an initial simulation model; performing relaxation operation on the molecular structure model in a high-temperature and high-pressure environment; performing irradiation damage simulation on the relaxed model based on molecular dynamics, selecting a central atom as a primary off-site atom, and setting incident energy and incident direction of the primary off-site atom to simulate atom cascade collision; keeping the incident direction unchanged, and adjusting the incident energy of the primary off-site atoms to obtain defect distribution and defect density under different energies; and analyzing the defect evolution law of the alloy in the high-temperature and high-pressure environment according to the simulation result. According to the method, the alloy material is observed from a microscopic atomic scale, so that a powerful support is provided for simulating a defect evolution process in a high-temperature and high-pressure environment and reflecting atomic collision of the alloy in a real radiation environment.

This application relates to a monolithically integrated multi-wavelength topological cavity surface-emitting laser (PCSEL) array. According to one embodiment, a monolithically integrated PCSEL array includes multiple PCSELs formed from the same semiconductor layer, at least one layer of which is formed as a photonic crystal layer, or the laser also includes a separate photonic crystal layer. The photonic crystal layer includes multiple supercell structures, each with substructures having multiple independent one-dimensional parameters. At least two independent one-dimensional parameters of one or more substructures are modulated to be greater than or less than their equilibrium position to open the Dirac point of the supercell's bandgap at the equilibrium position. Around any point in the photonic crystal layer, the modulation of the two independent one-dimensional parameters of the supercell forms a vortex structure, which corresponds in parameter space to one or more turns around the equilibrium position. The supercell lattice constants of the two lasers can be different to emit lasers of different wavelengths.

The invention relates to a method for constructing a deep learning potential function of a lithium alloy, which comprises the following steps of: establishing initial crystal models of magnesium-lithium alloys with different lithium contents, and carrying out structure optimization on the models to obtain equilibrium state lattice constants; and respectively constructing an elastic constant calculation model, a surface energy calculation model, an interstitial atom defect model and a vacancy defect model. The method comprises the following steps: applying a strain component, calculating a strain energy fitting elastic constant component, calculating surface energy after cutting a supercell structure and optimizing, calculating formation energy after determining a gap position, and introducing a vacancy to form the supercell structure and calculating the formation energy. And inputting the data set into a deep learning framework, optimizing model precision by adjusting truncation radius parameters, and finally generating a magnesium-lithium alloy deep learning potential function. Compared with the prior art, the method has the advantages that the problem that a classic MEAM potential function cannot accurately predict the variation trend of the basal plane fault energy along with the lithium content is solved, the defect of low calculation efficiency of a first principle is overcome, and the calculation efficiency close to that of an empirical potential function is realized.

A magnetoresistive random-access memory cell includes a first magnetic layer having a first lattice constant; a second magnetic layer having a second lattice constant; and a tunnel barrier between the first and second magnetic layers. The tunnel barrier includes at least one oxide layer with an oxide layer lattice constant. The oxide layer lattice constant has a mismatch smaller than six percent with at least one of the first and second lattice constants.

The invention provides a method for in-situ measurement of an internal stress state of an ultrathin film surface by using RHEED, and relates to the technical field of condensed state substance structure detection, and the method comprises the following steps: epitaxially growing an ultrathin film on a substrate by using film growth equipment; irradiating the ultrathin film by using an RHEED electron beam to obtain a diffraction pattern, and obtaining characteristic parameters of the diffraction pattern; obtaining the lattice constant of the ultrathin film through the characteristic parameters of the diffraction pattern; based on the lattice constant of the ultrathin film, the stress type and strain borne by the ultrathin film are determined. According to the method, the distance between diffraction fringes in a diffraction pattern is accurately extracted from a simple RHEED image, the lattice constant from the diffraction pattern is calculated, the stress state of the ultrathin film is accurately judged by comparing lattice constants in a stress-free state, existing equipment does not need to be greatly modified, and the method is simple and convenient to operate. The method can be realized only by using the existing RHEED electron beam and image processing software.

The application provides a yttrium barium copper oxide photonic crystal and a preparation method thereof. 7‑x The photonic crystal structure is composed of periodic yttrium barium copper oxide (YBa2Cu3O 7‑x ) superconducting material circular crystal columns, the lattice constant is 2630nm, and the radius of the circular crystal column is 500nm. The photonic crystal can change the position and width of the band gap by changing the light incidence angle, so that the middle infrared band gap is realized. The photonic crystal is prepared by adopting a magnetron sputtering method to prepare a yttrium barium copper oxide film on a strontium titanate single crystal substrate, and then adopting a focused ion beam method to process the yttrium barium copper oxide film into a periodic nanostructure composed of yttrium barium copper oxide circular crystal columns, so that the yttrium barium copper oxide photonic crystal is obtained. The preparation method of the yttrium barium copper oxide photonic crystal is simple and easy to control.

The invention relates to the technical field of semiconductor materials, and discloses an III-V wafer, a preparation method of the III-V wafer, an on-chip light source and a preparation method of the on-chip light source. The III-V wafer comprises a substrate (1), an epitaxial layer (2) and a strain superlattice layer (3), wherein the epitaxial layer (2) and the strain superlattice layer (3) are sequentially arranged on the substrate (1). Wherein the strained superlattice layer (3) comprises a strained superlattice layer I (31) and a strained superlattice layer II (32), the strained superlattice layer II (32) is in contact with the epitaxial layer (2), and the lattice constant of the material of the strained superlattice layer I (31) is smaller than that of the material of the strained superlattice layer II (32). According to the III-V wafer provided by the invention, the strain superlattice layers with different lattice constants are arranged on the epitaxial layer, so that interface defects can be eliminated, the luminous efficiency of an on-chip light source is improved, the service time of the on-chip light source is prolonged, and the reliability is enhanced.

The application relates to the technical field of semiconductor material preparation, in particular to a liquid phase epitaxial growth method and equipment for dynamically regulating lattice mismatch. The specific content is as follows: a substrate is pretreated to prepare micro pits and grooves of the substrate, and a uniform solution is prepared according to phase diagram information; a temperature gradient is set in a multi-zone temperature control epitaxial furnace, and the epitaxial growth of the substrate is controlled through a boat device; the substrate and the solution pool are sequentially moved into the furnace; during the epitaxial growth process, the lattice constant error, morphology and photoelectric properties of the growth are detected, and when the detection signal deviates from the predetermined threshold, the lattice mismatch is compensated by adjusting the solution concentration and the temperature; during the displacement process, the mother liquor remaining between different layers is poured into the grooves of the substrate through the inclined substrate. The application solves the problem of lattice mismatch control by real-time detection and real-time regulation of the lattice mismatch, and improves the quality and performance of the epitaxial layer.

The invention provides a positive electrode material, a positive plate and a lithium ion battery, the positive electrode material is a ternary layered oxide and comprises single crystal particles and polycrystal particles, the mass ratio of the polycrystal particles to the single crystal particles satisfies 9: 1-6: 4, the positive electrode material has a chemical general formula LiNixCoyMzO2, M is Mn or Al, x is more than or equal to 0.80 and less than or equal to 0.95, y is more than 0 and less than 0.25, and z is more than 0 and less than 0.2; the polycrystalline particles are secondary particles formed by sintering and agglomerating primary crystal grains at a high temperature, and the particle size of the primary crystal grains meets the following conditions: the shortest Freight diameter A is more than or equal to 0.1 mu m and less than or equal to 0.6 mu m; the longest Feret diameter B is greater than or equal to 0.2 mu m and less than or equal to 1.0 mu m; an aspect ratio B / A: 1.0 < = B / A < = 3.5; the morphology of the polycrystalline particles meets the relational expression that (B / A) * e ((k * c / a)) is larger than or equal to 30 and smaller than or equal to 100, and c / a is the lattice constant ratio of the polycrystalline particles; and k is the ratio of I003 to I104. According to the control standard for monitoring the two-dimensional microtopography of the primary crystal grains and the secondary particles of the polycrystalline particles by using a relational expression that (B / A). E ((k. C / a)) is greater than or equal to 30 and less than or equal to 100, the electrochemical performance of the positive electrode material can be evaluated more accurately, and the performance standardization control effect of a terminal battery product is improved.

The hydrogen separation filter includes a porous substrate and a super lattice layer on the porous substrate. The super lattice layer includes at least one lattice expansion layer containing a first material and at least two hydrogen dissociation and permeation layers containing a second material selected from the group consisting of Pd, V, Ta, Ti, Nb, and alloys thereof. The at least one lattice expansion layer and the at least two hydrogen dissociation and permeation layers are alternately stacked. The first material and the second material have a same crystalline structure. A lattice constant a1,bulk of a first bulk material haying a same composition and a same crystalline structure as the first material and a lattice constant a2,bulk of a second bulk material having a same composition and a same crystalline structure as the second material satisfy Formula (1):1.03a2,bulk≤a1,bulk≤1.15a2,bulk  (1).

In quantum devices with Josephson junctions, the generation of TLS defects and the variation in their characteristics are suppressed. [Solution] A first superconductor film, a second superconductor film, a first insulator film, and a third superconductor film, each having a cubic crystal structure, are sequentially formed by epitaxial growth on the (100) or (111) plane of a substrate having a cubic crystal structure. The second superconductor film, the first insulator film, and the third superconductor film are patterned to form a stack including the second superconductor film, the first insulator film, and the third superconductor film. The first superconductor film is patterned using the stack as a mask. After patterning the first superconductor film, the side surfaces of the stack are wet-etched. A second insulator film is formed to cover the wet-etched side surfaces of the stack. After forming the second insulator film, a fourth superconductor film is formed in contact with the third superconductor film. The stack forms a Josephson junction, and the first superconductor film has a lattice constant between that of the substrate and that of the second superconductor film.

This invention provides an antimonide HEMT structure, an epitaxial structure, and a method for preparing the same. By forming InSb channel layers on both sides of an InAs channel layer, the InSb material, due to its higher lattice constant than InAs and GaSb, exerts tensile stress on the InAs and GaSb layers on either side during growth. This improves the flatness of the interfaces between the InSb and InAs layers, and between the InSb and GaSb layers, and effectively reduces dislocation density, thereby increasing the electron mobility of the quantum well. Simultaneously, inserting a GaSb layer between the InSb and AlSb layers effectively prevents the high-temperature growth of the AlSb layer from affecting the precipitation of In atoms in the InSb and InAs layers. Furthermore, the lattice constant mismatch between the GaSb and AlSb layers is very small, further reducing dislocations and improving the quality of the active layer. Additionally, the InAs composite channel layer structure can form a stepped square quantum well, effectively increasing the concentration of 2DEG.

A method of forming a ceramic matrix composite includes arranging a plurality of fibers into a preform, each of the plurality of fibers being formed from silicon carbide, depositing a nucleating layer on the plurality of fibers, the nucleating layer comprising a crystalline material having an a-lattice constant and a c-lattice constant, and depositing a boron nitride layer on the nucleating layer. The c-lattice constant of the crystalline material of the nucleating layer corresponds to an a-lattice constant of the silicon carbide, such that the c-lattice constant of the crystalline material is within 3.0% of the a-lattice constant of the silicon carbide.

A method includes forming a fin in a substrate. The fin is etched to create a source / drain recess. A source / drain feature is formed in the source / drain recess, in which a lattice constant of the source / drain feature is greater than a lattice constant of the fin. An epitaxy coat is grown over the source / drain feature, in which a lattice constant of the epitaxy coat is smaller than a lattice constant of the fin.

The invention discloses a growth method for an epitaxial structure of a group III nitride heterojunction material system. The method comprises the following steps: determining a material of an insertion layer according to an in-plane lattice constant of a template layer and an in-plane lattice constant of a target epitaxial layer; based on the determined material of the insertion layer, selecting a first preset temperature to grow on the upper surface of the template layer to obtain the insertion layer with a preset thickness; and based on the insertion layer with the preset thickness, annealing recrystallization treatment is firstly carried out at a second preset temperature within a first preset time range, and then growth of a target epitaxial layer is carried out. According to the invention, the stress state required by the epitaxial layer can be accurately and reasonably controlled through the appropriate growth temperature and growth thickness of the insertion layer, so that high-quality growth of the target epitaxial structure is realized. The growth method for the epitaxial structure of the III-group nitride heterojunction material system can be widely applied to the technical field of epitaxial growth of materials.

A positive electrode active material for lithium-ion secondary batteries that offers high capacity and excellent charge-discharge cycle characteristics. provide. [Solution] A device containing lithium, cobalt, magnesium, oxygen, and fluorine, C Rietveld analysis was performed on the patterns obtained by powder X-ray diffraction using uKα1 rays. When this occurs, the crystal structure has a space group of R-3m, and the lattice constant of the a-axis is 2.814. Greater than ×10⁻¹⁰ m and less than 2.817 × 10⁻¹⁰ m, and c-axis The lattice constant is greater than 14.05 × 10⁻¹⁰ m, which is 14.07 × 10⁻¹⁰. When m is smaller and analyzed by X-ray photoelectron spectroscopy, the magnesium concentration when the cobalt concentration is set to 1 is... The positive electrode active material has a relative um concentration of 1.6 to 6.0.

The application discloses a chromium-doped yttrium oxide crystal material and a structural design method thereof, and belongs to the technical field of inorganic photoelectric functional crystal materials. + The crystal is of R3 trigonal crystal system minimum energy structure, Cr 9‑ The molar doping percentage is 3.125%, occupies a 1b Wyckoff site in a crystal lattice gap, forms [CrO6] 9‑ Regular octahedral coordination, Cr-O bond length is 2.073 angstrom; lattice constants a=b=10.4957 angstrom, c=18.1750 angstrom, a Γ point direct band gap is 3.23 eV, there is no virtual frequency in a phonon spectrum, dynamics is stable, simulated XRD is matched with an experimental spectrum, and Cr-O and Y-O bonds are all ionic bonds. The application realizes accurate determination of a ground state structure, stability verification and electronic property analysis by adopting CALYPSO structure prediction combined with first principle calculation, provides a standardized theoretical design process, and can be used for efficient development of photoelectric functional materials such as solid-state lasers, white light LEDs, solar cells and the like.

A positive electrode active material contained in this non-aqueous electrolyte secondary battery has an O3 structure and is represented by the compositional formula LixNayNiaMnbMe1-a-bOz, where Me is at least one element selected from the group consisting of main-group elements and transition metal elements other than Li, Na, Ni, and Mn, 0.8≤x≤1.15, 0<y≤0.2, 0.8<x+y≤1.35, 0<a≤1, 0≤b<1, 0≤1-a-b<1, and z is a value satisfying electroneutrality, wherein the lattice constant c indicating the c axis length of a crystal structure obtained from the results of analysis of an X-ray diffraction pattern acquired by X-ray diffraction satisfies the relation 14.465-0.25×a[Å]≤c≤14.635-0.25×a[Å].

The embodiment of the invention relates to a preparation method of an epitaxial structure, the epitaxial structure, a preparation method of an HEMT (High Electron Mobility Transistor) device and the HEMT device. The method comprises the following steps: providing a substrate; a BxAl1-xN nucleating layer is grown on the substrate in an epitaxial mode, and x is larger than 0 and smaller than or equal to 1; a ByAl1-yN gradient buffer layer is grown on the BxAl1-xN nucleating layer in an epitaxial mode, y is larger than or equal to 0 and smaller than or equal to 1, and in the direction away from the substrate, y is reduced from y0 to y2 and then increased to y1 or increased to y3 and then reduced to y1; an MzGa1-zN epitaxial layer is grown on the ByAl1-yN gradient buffer layer in an epitaxial mode, z is larger than or equal to 0 and smaller than 1, M comprises at least one of B, Al, In and Ti, and the difference between the lattice constant of By1Al1-y1N and the lattice constant of MzGa1-zN is smaller than the difference between the lattice constant of By2Al1-y2N or the lattice constant of By3Al1-y3N and the lattice constant of MzGa1-zN. Therefore, the formation of a high-quality MzGa1-zN epitaxial layer is facilitated, and the quality of a GaN device is effectively guaranteed.

The invention discloses a calculation method of a rare earth oxide molecule simulation force field and a glass component modulus performance evaluation method, and the method comprises the steps: collecting parameters in a crystal database in a rare earth oxide crystal state, including lattice constants, space group numbers, stiffness matrix coefficients and density; establishing a potential energy relation model between rare earth oxide cations and oxygen atoms; fitting parameters of the potential energy relation model; constructing a rare earth oxide molecule simulation force field; collecting glass components and modulus performance data in the glass performance database; and calculating the modulus performance of the glass component by applying the rare earth oxide molecule simulation force field obtained by the calculation method of the rare earth oxide molecule simulation force field and combining a molecular dynamics simulation technology. According to the fitting method provided by the invention, the molecular simulation force field for accurately simulating the rare earth oxide can be obtained, and the Young modulus of the fiber glass containing the rare earth oxide is favorably simulated and calculated.

The invention discloses a metal intercalation boron-carbon superconducting material GeB2C2 under normal pressure and a preparation method of the metal intercalation boron-carbon superconducting material GeB2C2. The material has a two-dimensional Kagome lattice structure, the space group is P6 / mmm (No.191), the lattice constants are a = b = 2.732, and c = 16.784. Through calculation and prediction of a first principle, the material has a superconducting transition temperature of about 48 K under a normal pressure (0 GPa) condition, and is dynamically stable. The superconducting mechanism is derived from a strong electroacoustic coupling effect, and the coupling constant lambda is about 1.64. The material is composed of Ge, B and C elements rich in earth crust, the raw materials are easy to obtain, the cost is low, and the large-scale preparation potential is achieved. Compared with a traditional normal-pressure superconducting material, the material disclosed by the invention has a relatively high superconducting transition temperature; compared with a high-voltage superconductor, a high-voltage environment is not needed, and the preparation and application threshold is remarkably reduced. The material can be applied to the fields of high-performance superconducting filters, superconducting nanowire single-photon detectors, small superconducting magnets and the like, and has important scientific research values and good practical application prospects.

The invention provides a single crystal thin film and a preparation method and application thereof. The single crystal thin film comprises a functional layer, a transition layer and a substrate which are sequentially stacked, wherein the material of the functional layer comprises at least one of lithium niobate single crystals and lithium tantalate single crystals; the absolute value of the difference between the lattice constant of the transition layer and the lattice constant of the functional layer is less than or equal to 5%; the absolute value of the difference between the lattice constant of the transition layer and the lattice constant of the substrate is smaller than or equal to 5%. The single crystal film provided by the invention not only has a relatively large size, but also is excellent in yield.

A spin current magnetization rotating element includes: a first ferromagnetic layer having a variable magnetization direction; and a spin orbit moment wiring layer adjacent to the first ferromagnetic layer. At least one element in the spin-orbit moment wiring layer has a crystal structure in which when dimensions of lattice constants of the crystal structure are represented by a, b, and c: atoms occupy internal coordinates: (0, 0, 0), (0.5, 0.5, 0), (0.25, 0.75, 0.25), (0.75, 0.25, 0.25), (0, 0.5, 0.5), (0.5, 0, 0.5), (0.75, 0.75, 0.75), and (0.25, 0.25, 0.75); the ab planes are laminated to have a quadruple helix structure along the c-axis; the angle (gamma) between the a-axis and the b-axis is in the range of 60 DEG < = gamma < = 120 DEG, and the ratio of b to a (b / a) is in the range of 0.2 < = b / a < = 1.0.

A method of forming a perovskite superlattice includes providing a single crystal substrate. The single crystal substrate is exposed to a precursor composition having ions and molecules therein of which a perovskite is composed to thereby form a perovskite superlattice on the single crystal substrate. The perovskite superlattice includes at least one series of layers having alternating inorganic slabs and organic spacers. The single crystal substrate and the inorganic slabs have lattice constants that differ from one another by less than a prescribed amount.

The invention discloses a hydrogen-based superconducting material Na2GaCuH6 with a double perovskite structure under normal pressure and a preparation method of the hydrogen-based superconducting material Na2GaCuH6. The material has an Fm-3m space group, the lattice constant is calculated and predicted through the first principle, and the material has the superconducting transition temperature of 42.04 K under the normal pressure condition. The material is composed of four common elements of Na, Ga, Cu and H, and the cost is low; the double perovskite structure is stable in thermodynamics and dynamics under normal pressure; the electro-acoustic coupling constant lambda is approximately equal to 0.98, and medium-intensity electro-acoustic coupling is achieved. Compared with an existing high-voltage hydride superconductor, the material can work without high-voltage equipment, and the preparation and application cost is greatly reduced; compared with a traditional normal-pressure superconductor, the superconductor has a higher Tc value. The material can be applied to the fields of low-temperature superconducting devices, superconducting magnets, quantum computing and the like, and has important scientific research value and application prospect.

The present invention relates to a thick-film resistor comprising ruthenium oxide and glass, the ruthenium oxide having a rutile-type crystal structure, and having Lc / La of 0.6885 or more and a crystallite diameter of 10 nm to 80 nm (inclusive) when the lattice constant of the a-axis as measured by X-ray diffraction is La and the lattice constant of the c-axis as measured by X-ray diffraction is Lc.

A magnetoresistive random-access memory cell includes a templating layer. The templating layer includes a binary alloy having an alternating layer lattice structure. The cell further includes a half metallic Heusler layer including a half metallic Heusler material having a tetragonal lattice structure. The half metallic Heusler layer is located outward of the templating layer, and has a Heusler in-plane lattice constant that is different from an in-plane lattice constant in a cubic form of the half metallic Heusler material. A tunnel barrier is located outward of the half metallic Heusler layer, and a magnetic layer is located outward of the tunnel barrier.

The application discloses a vertical cavity surface emitting laser and a manufacturing method thereof. The laser comprises a GaAs substrate, a first DBR layer formed on the GaAs substrate, an oxidation layer formed on the first DBR layer, a lattice gradient layer formed on the oxidation layer, a cladding layer formed on the lattice gradient layer, wherein the cladding layer comprises a first cladding layer and a second cladding layer stacked, a gain layer formed between the first cladding layer and the second cladding layer, and a second DBR layer formed on the cladding layer. The lattice gradient layer has different lattice constants in the thickness direction, and the lattice constant of the side of the lattice gradient layer close to the GaAs substrate matches the lattice constant of the GaAs substrate, and the lattice constant of the side of the lattice gradient layer close to the gain layer matches the lattice constant of the gain layer. The vertical cavity surface emitting laser and the manufacturing method thereof can flexibly expand the lasing wavelength to 1500 nm or above.

The invention relates to the technical field of single crystal films, in particular to a multi-layer composite single crystal film and a heteroepitaxy method thereof, the difference value a of lattice constants between film layers is smaller than or equal to 0.01, and the growth temperature Tg of the single crystal film of the next layer is lower than the saturation temperature Ts of the single crystal film of the previous layer. Components and growth temperatures of different film layers are formed through different formulas, in the growth process, the growth temperature Tg of the next layer of single crystal film is lower than the saturation temperature Ts of the previous layer of single crystal film, otherwise, the previous layer of film is dissolved, grinding and polishing treatment needs to be carried out after each layer of single crystal film is grown, and the problem that the prior layer of film is dissolved is solved. The influence of surface damage on the next layer of single crystal film is reduced, and the formed multi-layer composite single crystal film lays a foundation for subsequent planarization device application.