48 results about "Cr doped" patented technology

A perpendicular magnetic recording medium having a substrate, a Cr-doped Fe-alloy-containing underlayer containing about 8 to 18 at % Cr and a perpendicular recording magnetic layer, and a process for improving corrosion resistance of the recording medium and for manufacturing the recording medium are disclosed.

The invention discloses a method for preparing a corrosion-resistant antifriction Cr-doped DLC (diamond-like carbon) coating. The method comprises the steps of placing a pretreated substrate on a rotating stand rod of arc and magnetron sputtering composite deposition equipment, taking a post arc Cr target as a Cr source and three pairs of flat targets C targets as C sources, and installing the three pairs of flat targets C on the inner wall of a furnace body in an opposite manner; adopting high-purity Ar as a main ionization gas to guarantee an effective glow discharge process; and adopting high-purity N2 as a reacting gas, ionizing the reacting gas and combining the reacting gas with Cr and C elements to deposit on the surface of the substrate so as to form the Cr-doped DLC coating. The prepared Cr-doped DLC coating has a smooth and compact surface, hardness of 20 GPa, binding force with the substrate of 80N, coating thickness of 2.0 micrometers, and excellent corrosion resistance and antifriction performance.

The Cr-doped graphite coating consists of Cr in 3-8 wt% and amorphous graphite, has thickness of 1.0-1.5 microns, and possesses hardness as high as 1500-2200 HV, frication coefficient as low as 0.08-0.12 and self-lubricating function. The Cr-doped graphite coating is prepared with one four-target closed field unequilibrated magnetically controlled sputtering equipment and through the steps of vacuumizing, ion bombardment to clean, coating, etc. The process of preparing antifriction Cr-doped graphite coating is simple, stable and able to making high precision antifriction coating.

The invention discloses a ternary composite visible light photocatalyst, a preparation method and application thereof. The catalyst is an Ag3PO4/reduced graphene oxide/La and Cr-doped SiTiO3 ternary compound. Ag3PO4 is coated by the reduced graphene oxide; and La and Cr-doped SrTiO3 particles are distributed outside the reduced graphene oxide. The photocatalyst prepared by invention is high in catalytic activity and strong in stability, has ultrahigh degradation efficiency for dyes such as rhodamine B, and can carry out efficient degradation directly under natural light.

The invention provides a Cr-doped Ge2Sb2Te5 phase change material, a phase change memory unit and a preparation method. The ingredient general formula of the Cr-doped Ge2Sb2Te5 phase change material is CrxGe2Sb2Te5, wherein x is an atomic ratio of the Cr element, and x is more than 0.5 and less than 1.5. Cr doping in Ge2Sb2Te5 is carried out, Cr is a kind of metal with an extremely high melting point, heat stability of a phase change material can be raised, Cr can form bonds with Ge, Sb and Te, so segregation is avoided effectively. Under action of external energy, the Cr-doped Ge2Sb2Te5 phase change material can achieve reversible conversion between high resistance state and low resistance state, and the resistance value ratio of the high resistance state to the low resistance state can reach about two orders of magnitudes. When the phase change material is employed as a memory media of a phase change memory, the phase change memory unit has advantages of fast phase change speed, low write operation current and the like, and high temperature data retentivity and reliability of the device are raised greatly. The phase change memory employing the phase change memory unit structure has advantages of high speed, low power consumption, good data retentivity and the like.

The invention provides a method for preparing a chromium-doped titanium dioxide (TiO2)(CrxTi<1-X>O2) room-temperature ferromagnetic film, which belongs to the field of the preparation of the novel semiconductor spin electric devices. In the method, a Cr-doped titanium dioxide sol is first prepared adopting the sol-gel method and the sol is rotationally coated on a silicon substrate to form a CrxTi<1-X>O2 sol-gel film. The CrxTi<1-X>O2 sol-gel film has weak ferromagnetic characteristic at the room temperature after being annealed and crystallized in the air atmosphere; the CrxTi<1-X>O2 film has increased ferromagnetic characteristic after being secondarily annealed in the atmosphere in which the hydrogen is contained or under a vacuum environment. The adoption of the invention can prepare the CrxTi<1-X>O2 film having favorable room-temperature ferromagnetism.

The invention discloses a coke oven flue gas denitration catalyst and a preparation method thereof. The preparation method utilizes ammonium metavanadate as an active precursor, chromium nitrate as an auxiliary agent and oxalic acid and hydrochloric acid as reducing agents, and utilizes phosphoric acid to adjust and control the surface acidity of an active component. The preparation method comprises stirring, water bath heating, drying, calcining to obtain a Cr-doped oxyvanadium phosphate active component, adding the Cr-doped oxyvanadium phosphate active component and anatase TiO2 as a carrier with a specific surface area of greater than or equal to 250 m<2>/g into distilled water according to a ratio, carrying out stirring mixing, and carrying out water bath drying and calcining to obtain the catalyst. The catalyst utilizes phosphoric acid to adjust and control the surface acidity of the catalyst, and utilizes aid chromic nitrate to form an intercalation structure and promote formation of adjacent V<5+> and V<4+>. The catalyst has good low temperature denitration activity and strong SO2 and steam poisoning resistance and is suitable for industrial coke oven flue gas denitrification.

The invention relates to a preparation method of a Cr-doped TiO2 nanometer magnetic film with a room-temperature ferromagnetic effect, belonging to the technical field of a functionalized material. The preparation method comprises the steps of: by taking a TiO2 nanotube array thin film, prepared by but not limited to electrochemical anode oxidization technology, as a starting material, firstly carrying out CrNO3 aqueous solution soaked novel homogeneous-phase low-temperature Cr doping, then carrying out high-temperature annealing treatment, introducing composite vacancy and oxygen vacancy defects into the TiO2 nanotube array thin film, to obtain the TiO2 nanometer magnetic film which is high in room-temperature ferromagnetic property and controllability, low in cost, good in repeatability and can be manufactured in large scale. The preparation method has the characteristics of simple technology, low cost and good controllability and is suitable for mass production.

The invention discloses a Cr-doped perovskite structure halide near infrared light-emitting material and a preparation method thereof. The chemical composition is AB1-xX3:xCr<3+>, wherein A:B:X is equal to 1:1:3; A is at least one of Cs and Rb; B is at least one of Ag, Na, In, Ga and Pb; X is at least one of Cl and Br; and x is more than 0 and less than 100 mole percent. The invention also discloses the preparation method of the near infrared light-emitting material. The preparation method comprises the following steps: (1) weighing materials: weighing an A-containing compound, a B-containingcompound and a Cr-containing compound separately; and (2) grinding and uniformly mixing the materials and performing high-temperature calcining synthesis by a solid phase method. An emission band of the near infrared light-emitting material is positioned at 800 to 1400 nm and the emission peak is positioned at about 950 to 1050 nm. The preparation method is simple in process, low in raw material price, easy in large-scale technical promotion and is of great importance in research and development of near infrared fluorescent powder with wide spectrum emission. The light-emitting material can beused for manufacturing near infrared light-emitting devices and can be applied in the fields of spectral transformation, radioactive labeling, anti-faking and the like.

The invention relates to a method for analyzing the content and distribution of Cr in a Cr-doped zinc sulfide crystalline material. According to the method, laser denudation inductively coupled plasma massspectrometry is utilized for analyzing the content and distribution of Cr in the Cr-doped zinc sulfide crystalline material. The method comprises the step that 1, the surface of a ZnS matrix material is plated with a Cr film to prepare a plurality of Cr:ZnS solid standard substances with different Cr contents, wherein Cr is evenly distributed in the Cr:ZnS solid standard substances; 2, the contents of Cr in the solid standard substances are obtained through inductively coupled plasma atomic emission spectrometry or the inductively coupled plasma massspectrometry, the response signal strength of Cr in the solid standard substances is measured through the laser denudation inductively coupled plasma massspectrometry, and a Cr standard work curve is drawn; 3, laser denudation inductively coupled plasma mass spectrometric detection is carried out on a Cr-doped zinc sulfide crystalline material sample to be detected, and the content and distribution of Cr in the sample to be detected are obtained.

The invention discloses a Cr-doped near-infrared long-afterglow luminescent material with a perovskite structure. A substrate material of the luminescent material is ABO3, wherein A is Ca, Sr or Ba, B is Sn or Ti, and 0.001 to 5 mol% of Cr<3+> is doped in the substrate material. The invention further discloses a preparation method for the near-infrared long-afterglow luminescent material. The method comprises the following steps: (1) separately weighing a compound containing A, a compound containing Ti and a compound containing Cr; and (2) after grinding and uniform mixing of the above compounds, presintering the obtained mixture in the air/reductive atmosphere, then grinding the mixture again and carrying out sintering in the air/reductive atmosphere for a plurality of hours. The near-infrared long-afterglow luminescent material prepared in the invention has an emission band located at 650 to 850 nm, an emission peak at 760 nm and afterglow time of as long as 100 min. The preparation method is simple, uses cheap raw materials and can easily realize large-scale technical popularization.

The invention discloses a technological method for preparing Cr-doped beta-FeSi2 films on the basis of a magnetron sputtering method. The technological method comprises the following steps: firstly, rinsing a Si sheet; secondly, depositing a Cr/Fe or Fe/Cr double-layer film or a Fe/Cr/Fe multi-layer film on the substrate of the Si sheet by using the magnetron sputtering method, wherein the content of Cr is controlled by regulating the sputtering rate of each layer and the thickness of the film layer, so that the content of Cr substituting Fe is 1% to 5%; and thirdly, annealing the Cr/Fe or Fe/Cr double-layer film or the Fe/Cr/Fe multi-layer film deposited by using the magnetron sputtering method in a vacuum annealing furnace, so as to obtain the Cr-doped beta-FeSi2 film. According to the XRD (X-ray diffraction) measurement, the crystal structure of beta-FeSi2 is not changed by doping.

The invention provides a method for preferred orientation growth of rutile titanium dioxide nanowire arrays on a crystal face (001). The method comprises the following steps of 1) preparing a Cr-dopedtitanium dioxide film as a seed layer; 2) placing the Cr-doped titanium dioxide film seed layer prepared in the step 1) in growth liquid, carrying out hydrothermal growing, and obtaining the preferred orientation growth rutile titanium dioxide nanowire arrays. The method is low in cost, simple in process requirement, good in repeatability and capable of achieving large-scale manufacturing, and the prepared titanium dioxide nanowire arrays have good preferential orientation growth and ultraviolet excited light emitting characteristics in the (001) direction.

The invention discloses a coating micro-drilling knife for printed circuit board machining. The coating micro-drilling knife comprises a micro-drilling knife base body, wherein a metallurgical bondinglayer, a transition layer, a main wear-resistant layer and a self-lubricating layer are sequentially attached to the micro-drilling knife base body from inside to outside; and the metallurgical bonding layer is a pure metal Cr layer, the transition layer is a nano multilayer formed by alternating Cr and Vn, the main wear-resistant layer is a nano multilayer formed by alternating DLC and VN, and the self-lubricating layer is a Cr-doped DLC layer. According to the coating structure, on one hand, the composite coating has relatively high performance; and on the other hand, the coating and the base body can have good adhesive force; and meanwhile, operability is simple and feasible. The coating micro-drilling knife has good film-base binding force, high hardness (greater than 20 GPa) and lowfriction coefficient (less than 0.3).

The invention relates to a Cr-doped heterojunction spin field effect transistor and a preparation method thereof. The preparation method comprises: selecting a sapphire substrate; growing a Ga2O3 epitaxial layer on the surface of the sapphire substrate by employing a MBE process; injecting Cr ions into the Ga2O3 epitaxial layer to form a source region and a drain region; fabricating an ohmic contact source electrode and a drain electrode on the surfaces of the source region and the drain region; growing a separating layer on the surface of the Ga2O3 epitaxial layer by employing a PECVD process; and fabricating a Schottky contact gate electrode on the surface of the Ga2O3 epitaxial layer to accomplish the preparation of the spin field effect transistor. According to the Cr-doped heterojunction spin field effect transistor and the preparation method, the doping concentration and the defect concentration in source-drain materials can be changed through adjustment of the dosage of ion implantation and the annealing time so that the spin polarizability of the materials at a room temperature is optimized.

The invention relates to a preparation method of Cr-doped alpha-Fe2O3 micro-nano crystal, which relates to the technical fields of nano powder preparation and application. The method comprises two processes of preparation of a reaction precursor and a hydrothermal reaction, and is characterized in that 1 to 1.8 g of Na2CrO4 and 1.4 g of FeCl2.4H2O are added to 50 mL of deionized water, after stirring and dissolving, 0-1.2 g of hydroxylamine hydrochloride is added, and then a mixture is heated in an oven at a constant temperature to obtain Cr-doped alpha-Fe2O3 micro-nano crystal of a spindle shape or a dumbbell shape. The method adopts FeCl2.4H2O and Na2CrO4 as raw materials, and successfully prepares Cr-doped alpha-Fe2O3 micro-nano crystal by a hydrothermal reaction method, and the dumbbell-shaped Cr-doped alpha-Fe2O3 micro-nano crystal is obtained by using hydroxylamine hydrochloride. The method has the advantages of simple process, low cost, environmental friendliness and controllable shape, and is conducive to popularization and application.

The invention discloses a preparation method of a Cr-doped DLC coating. The advantages that the smoothness, uniformity and density of a high-power pulse magnetron sputtering film layer are high are sufficiently utilized, and a bottom layer and transition layer design method is adopted in order to overcome the defects that the binding force of the DLC coating and the toughness of the film layer arepoor. By means of the unique film system design and mixing process, it is guaranteed that the binding force of the coating is improved, and it is also guaranteed that the coating deposition rate, thecoating density and the wear resisting and friction reducing performance are improved. The appearance of the Cr-doped DLC coating prepared through the method is ash black, the surface is smooth and dense, the hardness of the coating is 32 GPa, the film-matrix binding force reaches 72 N, and the coating thickness is 1.45 micrometers. The dry friction coefficient of the coating is 0.2. It is shownthat the Cr-doped DLC coating has good wear resisting and friction reducing performance.

The invention discloses a novel photocatalyst for adsorbing and degrading azo dyes. The novel photocatalyst is Cr-doped ZnO containing a magnetic material and fixedly carried on optical fiber. A preparation method of the photocatalyst comprises the following steps of: (S1) preparing the Cr-doped ZnO containing the magnetic material: dissolving soluble zinc salt, chromium salt and ferric salt in alcohol to obtain solution A, adding alcohol solution of NaOH into the solution A, stirring, after heating for reaction, centrifugally separating, drying precipitates to obtain Cr-ZnO/gamma-Fe2O3; (S2)using the optical fiber to embed the Cr-ZnO/gamma-Fe2O3: (S21) removing an outer coating layer on the surface of the optical fiber, and exposing an optical-fiber core body; (S22) adopting a sol-gel method to embed Cr-ZnO/gamma-Fe2O3 on the surface of the optical-fiber core body to obtain the novel photocatalyst. The novel photocatalyst disclosed by the invention has the beneficial effects that thephotocatalyst is embedded on the surface of the optical fiber, so that the defect that the photocatalyst in the ordinary porous carrier hole can not be illuminated by light to cause waste of the photocatalyst is overcome, and the effective utilization rate of the photocatalyst is improved.