31results about How to "Raise the superconducting transition temperature" patented technology

The present invention relates to a superconducting nanowire single photon detector comprising a superconducting nanowire configured and arranged for incidence of photons on a region of the superconducting nanowire and for forming a local non-superconducting region or hot spot on the region. The superconducting nanowire is made of a high Tc cuprate superconductor material having a superconducting critical temperature above 77K. The invention also relates to a method of obtaining a superconducting nanowire single photon detector of the invention.

The invention provides a preparation method of an epitaxial iron-based superconducting thin film, comprising the following steps: a) preparing a target material needed by the epitaxial iron-based superconducting thin film, placing the target material into a vacuum cavity of a pulse laser deposition system, wherein the target material is FeSex or FeSe(1-y)Tey target material, x is more than or equal to 0.80 and is less than or equal to 1.0, y is more than 0 and is less than or equal to 1.0; b) preparing a substrate, fixing the substrate on a substrate platform, and placing the substrate platform into the vacuum cavity of the pulse laser deposition system; c) heating the substrate platform and further heating the substrate; and d) utilizing a pulse laser deposition method to grow the thin film on the substrate. The invention also provides a single-alpha-phase and c-oriented epitaxial iron-based superconducting thin film prepared according to the method.

The invention discloses a composite heterostructure superconducting material of polystyrene colloidal spheres and niobium films, comprising a substrate, a niobium film and a polystyrene colloid hexagonal array film, the niobium film is located on the substrate, and the polystyrene hexagonal array film The film is covered on the niobium film; the polystyrene hexagonal array film includes a plurality of polystyrene colloidal microspheres, and each polystyrene colloidal microsphere is closely arranged in a single layer to form a hexagonal array. The invention also discloses a preparation method of the superconducting material. In the present invention, polystyrene colloidal microspheres and niobium superconducting thin film materials are constructed as heterostructure nanostructure materials, and the critical temperature of superconducting transition is regulated by changing the contact area of ​​colloidal spheres and niobium substrates, thereby improving the superconductivity of niobium thin films. The conduction transition temperature Tconset, the material preparation process is simple, and the required equipment is less, which greatly reduces the preparation cost of the superconducting material and is conducive to popularization and application.

The invention relates to a method for improving the superconducting performance of a Sn-added FeSe0.5Te0.5 superconductor. The method comprises the steps of mixing Sn powder and FeSe0.5Te0.5 powder in a weight ratio of 0.05: 1, and sufficiently grinding the mixture in an agate mortar for 20-30 minutes; and then preparing into a flake under the pressure of 6-8MPa, finally putting the flake into a high-temperature differential scanning calorimeter, heating to 600 DEG C under the protection of flowing high-purity argon, preserving the heat for 5-10 hours, and cooling to room temperature. A fact that a Sn-Se-Te liquid phase generated by reaction between Sn and FeSe0.5Te0.5 can accelerate the transformation from a non-superconducting phase to a superconducting phase is discovered for the first time and is favorable for forming a superconducting laminar structure so that the superconducting transition temperature of the structure is finally significantly improved, thus providing an important clue for optimizing a preparation process of an iron-based superconductor, illuminating an iron-based superconducting mechanism and promoting the development of the superconducting theory.

The invention discloses a rapid preparation of Nb 3 The method of Al superconductor, the method includes the following steps: weighing Nb powder and Al powder according to the stoichiometric ratio of 74:26, and then fully mixing them in a planetary ball mill to obtain a mixed powder; placing the mixed powder in a discharge plasma Heat and pressure sintering at a temperature of 1200 ° C ~ 1400 ° C in a bulk sintering furnace to obtain Nb 3 Al superconductor; Nb after SPS sintering 3 The Al superconductor was put into a quartz tube for post-annealing at a temperature of 850°C to 950°C, and then cooled in the furnace after sintering to obtain post-annealed Nb 3 Al superconductor. Preparation of Nb provided by the present invention 3 The method of Al superconductor is novel, the production efficiency is high, and it is more energy-saving and environmentally friendly.

The invention relates to MgB doped with a heterogeneous phase of a topological light emitter 2 Based superconductor and its preparation method, using topological emitter doping to change MgB 2 The superconducting transition temperature of the base superconductor. The present invention adopts hydrothermal method to prepare three kinds of topological illuminants: micron sheet m-Y 2 O 3 :Eu 3+ / Ag, nanosheet n‑Y 2 O 3 :Eu 3+ / Ag and n-Y 2 O 3 :Eu 3+ / AgCl. Heterogeneous phase-doped MgB prepared by ex-situ doping 2 base superconductor. By changing the size of the dopant, the content of Ag and the mass fraction of the dopant, the change of the superconducting transition temperature of the doped sample was studied. In experiments, it was found that when using n‑Y 2 O 3 :Eu 3+ / AgCl as the dopant, and when the doping concentration is 1%, the doped MgB 2 The transition temperature of the base superconductor is higher than that of the corresponding pure MgB 2 sample.

The invention provides a method for preparing an electron-doped high-temperature superconductor La2-xCexCuO4 film. Direct current magnetron sputtering equipment is used, and the invention comprises the following steps: firstly, according to La2-xCexCuO4 and the compounding ratio that 0.08 is less than or equal to x and x is less than or equal to 0.16, a solid phase reaction method is adopted to prepare a La2-xCexCuO4 ceramic target, and then the ceramic target is arranged on the target seat of a reaction chamber; secondly, substrate choice: SrTiO3, MgO or LaAlO3 is chosen, washed to be clean and then put on a heating stage in the reaction chamber, and the reaction chamber is closed; thirdly, the reaction chamber is vacuumized till the vacuum of a back side is superior to 2.0*10<-4>Pa; fourthly, the substrate is heated to 600-800 DEG C; fifthly, a reacting gas is charged in the reaction chamber; sixthly, the surface of the La2-xCexCuO4 ceramic target is pre-sputtered; seventhly, the heating stage is moved to the target position, and the La2-xCexCuO4 film begins to be prepared on the substrate; eighthly, after the reaction is ended, the reacting gas is stopped to be charged, the vacuum is pumped till the vacuum degree is superior to 2*10<-4> Pa, then the temperature of the substrate with La2-xCexCuO4 film prepared is dropped to the annealing temperature, and the annealing is performed; ninthly, the substrate with La2-xCexCuO4 film prepared is naturally cooled to the room temperature.

The invention discloses a method for preparing magnesium diboride superconducting wire or strip by electron beam annealing. The method adopts electron beam to anneal the unphased MgB2 wire or strip precursor prepared by in-situ powder sleeve method in vacuum. Annealing, within the annealing time of several seconds to several minutes, the magnesium-boron mixed powder in the wire or strip precursor undergoes a chemical reaction to finally generate magnesium diboride superconducting wire or strip. Electron beam parameters and annealing time are determined according to different wire or strip precursor thickness and annealing temperature requirements during annealing, and the annealing of different diameter wires or strips is completed by precisely controlling the electron beam acceleration voltage, beam current and annealing time. The magnesium diboride superconducting wire or strip prepared by the invention has stable properties, fine and uniform crystal grains, uniform phase formation, and a transition temperature higher than 37K.

The present invention proposes a method for increasing the iron-selenium superconducting transition temperature by doping with niobium, mixing iron powder and selenium powder in an agate mortar, fully grinding to obtain a uniform mixed powder; then pressing the ground powder into tablets, and vacuum-sealed in a quartz tube; put the well-sealed quartz tube into a tubular sintering furnace, and obtain a FeSe block after sintering through a one-step sintering process, and then grind it into a powder in a mortar; mix pure Nb powder with the first step The obtained FeSe powder is ground and mixed according to the atomic percentage FeSe:Nb=1:x, x=0.02~0.08 to obtain a mixed powder; the mixed powder obtained in the second step is pressed into tablets, placed in a tube furnace, vacuumized and The tube is filled with high-purity argon for secondary sintering, and then cooled in a furnace to obtain a Nb-doped FeSe superconducting block. Nb doping can increase the superconducting transition temperature of FeSe to 13.6K.

The invention belongs to the technical field of superconductors, and in particular relates to a metal-based superconducting tape and a preparation method thereof. A method for preparing a metal-based superconducting tape, comprising the following steps: 1) using a pulsed laser deposition method to form a thin film on the surface of the metal-based tape; in the pulsed laser deposition method, using Fe (1‑x) Se y Te (1‑y) Target or Fe (1+x) Se y Te (1‑y) A target material, wherein 0≤x≤0.1, 0.1≤y≤0.9; 2) depositing a protective layer on the surface of the thin film by a magnetron sputtering method. The iron-based superconducting tape can be rapidly and continuously prepared by the method of the invention, and the prepared superconducting tape has good C-axis orientation, smooth surface, high superconducting transition temperature and high critical current density.

The invention discloses a method for quickly preparing high-quality FeSe0.5Te0.5 superconductive polycrystal. The method is characterized by comprising the following steps: a, blending Fe powder having the purity of 99% to 99.99%, Te block having the purity of 99% to 99.99% and Se particles having the purity of 99% to 99.99% together in an atomic ratio of 1: 0.5: 0.5 in air and putting the mixture in a quartz tube with one end sealed; b, sealing the other end of the quartz tube with the raw material powder by using an acetylene welding gun; c, putting the quartz tube with the raw material and both ends sealed into a larger-aperture quartz tube, and sealing the two ends of the larger-aperture quartz tube; and d, putting the larger-aperture quartz tube with both ends sealed into a box-type furnace for sintering at a temperature ranging from 850 to 880 DEG C for 3-5 days, and naturally cooling the box-type furnace to a room temperature, thereby obtaining the high-quality FeSe0.5Te0.5 superconductive polycrystals.

The invention relates to a method for improving the FeSe superconducting transition temperature by adding Mg. The method comprises the following steps of: milling Fe powder and Se powder in an agate mortar or a planetary ball mill at the atomic ratio of Fe:Se=1: (0.90-1.05), pressing the mixture to obtain a thin sheet, placing the thin sheet into a high temperature differential scanning calorimeter or a tubular sintering furnace, sintering the thin sheet in a thermally insulating mode at 600-700 DEG C for 18-48 hours, cooling the sintered thin sheet to room temperature, again milling the sintered FeSe block into powder, milling the Mg powder and the FeSe powder in the agate mortar or the ball mill at the atomic ratio of (0.2-1):1, pressing the mixed powder to obtain the thin sheet, sintering the thin sheet in the high temperature differential scanning calorimeter or the tubular sintering furnace in the thermally insulating mode at 700-800 DEG C for 0.5-1 hour, and cooling the sintered thin sheet to room temperature, wherein the MgSe coexists with the unreacted FeSe to influence the lattice constant of the FeSe so that the superconducting transition temperature of the FeSe is increased from 9.8K to 12.1K, and the increase range is above 20%.