65 results about "Magnesium doping" patented technology

The invention discloses a Ga2O3-baesd metal oxide semiconductor field effect transistor with good heat dissipation performance and a preparation method thereof, and belongs to the technical field of power semiconductor devices and preparation thereof. The device is formed by parts of a substrate, a Ga2O3 buffering layer, a Ga2O3 channel layer, a Ga2O3 source, a drain region, an Al2O3 insulation layer and a metal electrode, and is characterized in that the substrate is Si monocrystalline; a nitride and oxide mixed multilayer structure is prepared between the substrate and the Ga2O3 buffering layer; and the mixed multilayer structure is formed by a GaN-serial multilayer structure film, a Ga2O3 oxidation thin layer, an involuntary doped Ga2O3 lower buffering layer and a magnesium doped Ga2O3 semi-insulation layer. According to the invention, a heteroepitaxy problem of Ga2O3 materials is solved; disadvantages of poor heat dissipation performance and high selling price of the Ga2O3 monocrystalline substrate used by the current Ga2O3-baesd metal oxide semiconductor field effect transistor are overcome; and advantages of mature technology, low selling price, easy integration and good heat dissipation of the Si material can be used, so the provided Ga2O3-baesd metal oxide semiconductor field effect transistor is quite highly practical.

A III-nitride-based light emitting device having a multiple quantum well (MQW) structure and a method for fabricating the device, wherein at least one barrier in the MQW structure is doped with magnesium (Mg). The Mg doping of the barrier is accomplished by introducing a bis(cyclopentadienyl)magnesium (Cp₂Mg) flow during growth of the barrier using metalorganic chemical vapor deposition (MOCVD). The barriers of the MQW structure may be undoped, fully Mg-doped or partially Mg-doped. When the barrier is partially Mg-doped, only portions of the barrier are Mg-doped to prevent Mg diffusion into quantum wells of the MQW structure. The Mg-doped barriers preferably are high Al composition AlGaN barriers in nonpolar or semipolar devices.

The invention relates to a preparation method of a three-dimensional graphene/tungsten-based nanosheet/magnesium doped zinc oxide layer-by-layer assembly structure. According to the method, graphene, tungsten-based nanosheets, zinc acetate and magnesium acetate are used as raw materials, deionized water is used as a solvent and oxalic acid is used as a complexing agent, and a co-precipitation method and subsequent heat treatment are used to prepare the three-dimensional graphene/tungsten-based nanosheet/magnesium doped zinc oxide layer-by-layer assembly structure. The most important characteristic of the invention is that a mechanical shearing method is used to prepare a water-soluble tungsten-based nanosheet dispersed solution, and the three-dimensional graphene/tungsten-based nanosheet/magnesium doped zinc oxide layer-by-layer assembly structure is obtained in a water solution; the preparation process is simple and easy to realize scale production; meanwhile, the three-dimensional graphene/tungsten-based nanosheet structure has a good synergistic effect, and is more favorable for the separation of photo-induced electrons and electron-hole pairs in comparison with a homogenous material; the three-dimensional graphene/tungsten-based nanosheet/magnesium doped zinc oxide layer-by-layer assembly structure has good photocatalytic performance and can be applied to the fields of sewage treatment, photolysis of water, air purification and solar cells.

The invention provides an LED epitaxial layer, a growth method of the LED epitaxial layer and an LED chip. The LED epitaxial layer comprises an N-type confinement layer, an MQW layer and a P-type confinement layer, wherein the N-type confinement layer, the MQW layer and the P-type confinement layer grow in order, the MQW layer comprises a plurality of structure units, and each structure unit comprises an InGaN layer and a GaN layer. The LED epitaxial layer is characterized in that the inside of each structure unit further comprises at least one magnesium doping layer. According to the LED epitaxial layer, the magnesium doping layers are additionally arranged in multiple quantum wells, surfaces of GaN potential barriers are coarse, growth of InGaN potential wells is influenced, InGaN cross growth is inhibited, InGaN three-dimensional growth is promoted, and accordingly the number of quantum dots in InGaN is increased, and light-emitting efficiency of the LED chip is improved by 5%-6%.

The invention discloses a magnesium-doped enhanced GaN-based HEMT device and a preparation method thereof. The method comprises the following steps: (1) a gate electrode contact window is formed abovean AlxGa1-xN barrier layer in a photoetching mode; (2) metal magnesium is deposited on the photo-etched surface by adopting an electron beam evaporation/thermal evaporation/ magnetron sputtering method; (3) the unexposed photoresist is stripped by adopting a stripping process; (4) a thermal annealing process is carried out on an epitaxial wafer deposited with magnesium for performing diffusion doping of thermal annealing; and (5) the annealed surface metal magnesium is removed by preparing dilute hydrochloric acid to obtain the enhanced GaN-based HEMT device. According to the method, the metal magnesium thermal diffusion technology is utilized to realize the P-type doping of the AlxGa1-xN barrier layer below the gate electrode to prepare the enhanced GaN-based HEMT device. The preparationmethod has the advantages of being simple in process and low in cost, and has important significance for realizing the high-performance GaN-based HEMT devices.

The present invention relates to a method for preparing a ferrite superparamagnetic nano particle engineered by magnesium doping, and a technique for applying it to hyperthermia cancer cell treatment and the heat shock protein (HSP) self-defense mechanism.

The invention belongs to the technical field of electrochemistry, and particularly relates to a high-energy-density lithium iron phosphate battery. A positive electrode active material is selected from titanium/magnesium-doped lithium iron phosphate, the surface density of a positive plate is 190-210 g/m<2>, the compaction density is greater than or equal to 2.60 g/cc, a negative electrode active material is carbon-coated single particle and secondary particle needle coke blend artificial graphite, and the compaction density of a negative plate is greater than or equal to 1.70 g/cc. The density of the electrolyte is equal to 1.15 g/cc, the wall thickness of the aluminum shell body is 0.40-0.50 mm, a positive electrode current collector is an aluminum foil with the diameter of 12-13 [mu]m, a negative electrode current collector is a copper foil with the diameter of 4.5 [mu]m, a diaphragm is a 7 + 2C + 2P ceramic gluing diaphragm, a conductive binder is used for replacing a positive electrode, the addition amount is 1.0-2.0%, and the weight ratio of a positive electrode active material to a positive electrode dressing is greater than or equal to 98%. According to the invention, the energy density of the battery is greatly improved and reaches 200Wh/kg.

The invention relates to the field of battery material preparation methods, and discloses a preparation method of carbon-coated nitrogen-magnesium-doped porous silicon-based composite material and a lithium ion battery. The method comprises the steps of dropwise adding a carbon source solution into nano silicon dioxide powder, and carrying out high-temperature carbonization operation in a nitrogenatmosphere so as to obtain a carbon-coated nitrogen-doped silicon dioxide material; performing high-temperature reduction operation on the carbon-coated nitrogen-doped silicon dioxide material in a reducing atmosphere to obtain a carbon-coated nitrogen-doped silicon-based composite material; etching the carbon-coated nitrogen-doped silicon-based composite material to obtain a carbon-coated nitrogen-doped porous silicon-based composite material; carrying out ultrasonic dispersion operation on the carbon-coated nitrogen-doped porous silicon-based composite material to obtain a dispersed mixed turbid solution; and adding the dispersed mixed turbid solution into a magnesium source mixed solution, and carrying out separation, washing and drying operations to obtain the carbon-coated nitrogen-magnesium-doped porous silicon-based composite material. According to the method, volume expansion of silicon can be effectively inhibited, and the conductivity and the initial efficiency of the silicon-carbon material are effectively improved.

The invention discloses a three-dimensional porous titanium-based magnesium-doping coating and a preparing method thereof. Porous treatment is conducted on the surface of pure titanium or a titanium alloy matrix, and then the three-dimensional porous titanium-based magnesium-doping coating is formed through bioactive glass modification. The prepared three-dimensional porous titanium-based magnesium-doping coating has the advantages that elasticity modulus is close to that of hard bone tissue, bonding strength is high, chemical property is stable, the porous structure and bone induction elements are obtained, and new bone growth and combination are facilitated. In-situ generation of the porous structure is achieved on the surface of the surface of titanium or the titanium alloy matrix, and the pore size can be adjusted by adjusting electrolyte constitutes, concentration and technological conditions; pulse deposition of a magnesium-doping bioactive glass coating is conducted on the titanium-based porous structure, the deposition technique and target constituents are changed, and the microstructure and thickness of the coating and the content of magnesium in the coating are made controllable and adjustable. The preparing process is simple and quick, operation is convenient and controllable, and application and popularization are easy.

The invention discloses a nickel-cobalt-manganese precursor for a doped lithium ion battery. The precursor is a radial metal hydroxide, the chemical expression of the precursor is Ni0.7Co0.1Mn0.2-xMgx(OH)2, and the x is greater than or equal to 0.02 and less than or equal to 0.04. The invention also discloses a preparation method of the nickel-cobalt-manganese precursor. According to the preparation method, an Mg doping element is directly added in the coprecipitation process, so that the doping element can be uniformly distributed in precursor particles, the modification effect of the dopingelement is effectively exerted, and magnesium doping is beneficial to forming a good layered structure, enhancing the structural stability of the material and improving the cycle performance of the high-nickel ternary material.

The invention discloses preparation of a concentration gradient magnesium-doped lithium-rich manganese-based oxide and application of the concentration gradient magnesium-doped lithium-rich manganese-based oxide to a lithium battery, the chemical formula of the oxide is Li1.2-2x Mn0.54Ni0.13Co0.13MgxO2, and x is more than 0 and less than or equal to 0.07. the preparation method specifically comprises the following steps: (1) firstly, preparing a manganese salt, cobalt salt, nickel salt and transition metal salt mixed solution and an ammonia water and sodium carbonate mixed solution as a complexing agent and a precipitating agent according to a proportion, and injecting a magnesium salt solution into the transition metal salt mixed solution by utilizing a peristaltic pump; then adding the transition metal salt solution, a precipitator and a complexing agent into a reaction kettle through parallel flow to carry out a co-precipitation reaction to obtain precursor powder with elements distributed in a gradient manner; and (2) mixing and calcining the precursor powder and a lithium salt to obtain the concentration gradient magnesium-doped lithium-rich manganese-based positive electrode material. The gradient doping material is applied to the field of lithium batteries, and is high in discharge capacity and good in cycle performance. The preparation method disclosed by the invention is low in cost, the process has good compatibility with existing equipment, the potential of quantitative production is achieved, and relatively high industrialization value and wide application prospects are shown.

A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB₂ yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

The invention discloses a magnesium-doped metal-organic frame DMMg0.5Co0.5F single-crystal material and a preparation method thereof. The magnesium-doped metal-organic frame DMMg0.5Co0.5F single-crystal material is composed of a DMMg0.5Co0.5F single crystal with the size of 2.0*2.0*1.0-2.5*2.5*1.5 mm<3>, wherein the mol ratio of a magnesium ion to a cobalt ion in the compound is 1:1. The used reagent is a business product and is not prepared through a tedious preparation; a novel metal-organic frame single-crystal material and a large single crystal can be obtained through the combination of a hydrothermal method and a liquid phase method; and the process is strong in controllability and easy to operate and the purity of the obtained product is high. The magnesium-doped DMCoF single-crystal material obtained from the invention is expected to be widely used in a novel metal-organic frame semiconductor, information storage and an optical apparatus.

The invention discloses doped and coated composite modified lithium cobalt oxide LCMO@BT and a preparation method and application thereof. The method comprises: ball-milling and uniformly mixing a magnesium compound, a cobalt compound and a lithium salt; and presintering the mixture, calcining at high temperature, and cooling to obtain the magnesium-doped lithium cobalt oxide; then adding barium salt into the weak acid aqueous solution, and heating and stirring until the barium salt is dissolved; and sequentially adding titanate and magnesium-doped lithium cobalt oxide, heating, uniformly stirring, standing for layering, pouring out supernate, drying and carrying out vacuum drying; and calcining the mixture at a high temperature, and cooling to obtain a product LCMOS@BT which can be used as an ultrahigh-voltage lithium cobalt oxide positive electrode material of a lithium ion battery. The method provided by the invention has the advantages of cheap and easily available raw materials, low cost, short calcination time and high production efficiency, is very easily used for large-scale industrial production, and has wide application prospects.

The invention relates to the technical field of photoelectric materials, and discloses a magnesium-doped zinc oxide magnetron sputtering target material and a preparation method thereof. The preparation method comprises the steps that 1, zinc oxide powder is doped with magnesium oxide powder and third oxide powder, and then the mixed powder and an ethanol solution are mixed so as to form slurry; (2) ball milling is carried out on the slurry, and then drying and sieving are carried out so as to obtain powder for molding; (3) isostatic cool pressing is carried out on the powder so as to form a green body; and (4) the green body is slowly heated to 900-1150 DEG C, heat preservation is carried out for 30-90 minutes, then the green body is quickly heated to the sintering temperature of 1300-1450 DEG C, heat preservation is carried out for 120-480 minutes, slow cooling is carried out so as to form a semi-finished product, and cutting and polishing are carried out so to obtain the magnesium-doped zinc oxide magnetron sputtering target material. The target material has the advantages that the density is high, the relative density is greater than 95% or above, meanwhile, the electrical resistivity is low and can reach 4*10<-2>, the resistance of the target material is far lower than the resistance of a target material in the prior art, the conductive effect is good, and the requirement for medium-frequency rapid sputtering of a coating production line can be met.

The invention relates to the technical field of electrode materials of lithium ion batteries, and provides a preparation method for magnesium-doped cobalt liquid. The preparation method comprises the following steps: carrying out extraction treatment on a cobalt-containing water phase treated by a P507 organic phase and a P204 organic phase to obtain a first P507 organic phase containing cobalt and magnesium, carrying out first reverse magnesium extraction treatment on the first P507 organic phase to remove most of impurity magnesium in the first P507 organic phase and to obtain a second P507 organic phase containing cobalt and the remaining part of magnesium, performing reverse magnesium extraction treatment on the remaining part of magnesium in the second P507 organic phase, and then performing reverse cobalt extraction treatment on the second P507 organic phase to obtain magnesium-doped cobalt liquid doped with different magnesium. The magnesium-doped cobalt liquid provided by the invention can be used as a raw material of a nickel-cobalt-manganese ternary precursor, and nickel-cobalt-manganese ternary precursors with different magnesium doping amounts can be prepared, so impurity magnesium in cobalt ore can be effectively utilized in a production process, and production cost is saved.

The invention discloses magnesium-doped lithium iron phosphate/carbon composite microspheres with high tap density and a preparation method and application thereof, and belongs to the technical field of lithium batteries, and the preparation method comprises the following preparation steps: (1) weighing a proper amount of an iron source, a phosphorus source, a lithium source, magnesium hydroxide, PEG-400 and a carbon source A, and performing solid-phase mixing to obtain a mixture, adding the mixture into deionized water containing zircon sand for ball milling, and filtering and separating the zircon sand by using a screen after ball milling to obtain slurry; (2) carrying out spray drying treatment on the slurry obtained in the step (1) to obtain yellowish-brown precursor powder; and (3) placing the yellowish-brown precursor powder obtained in the step (2) in a tubular furnace rich in inert gas for high-temperature sintering to obtain the high-tap-density magnesium-doped lithium iron phosphate/carbon composite microballoon.The composite material obtained by the preparation method has the advantages of high electronic conductivity and ion diffusivity, good rate capability and cycle performance, high tap density, high specific surface area, high specific surface area and the like. The material can be used for producing middle-large capacity and middle-high power lithium ion batteries, and industrialization of the material can be promoted.