Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N60/00—Superconducting devices
  • H10N60/80—Constructional details
  • H10N60/85—Superconducting active materials
  • H10N60/855—Ceramic superconductors
  • H10N60/857—Ceramic superconductors comprising copper oxide
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/45—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides
  • C04B35/4504—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides containing rare earth oxides
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/45—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides
  • C04B35/4521—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides containing bismuth oxide
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N60/00—Superconducting devices
  • H10N60/01—Manufacture or treatment
  • H10N60/0268—Manufacture or treatment of devices comprising copper oxide
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/725—Process of making or treating high tc, above 30 k, superconducting shaped material, article, or device
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/775—High tc, above 30 k, superconducting material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/775—High tc, above 30 k, superconducting material
  • Y10S505/776—Containing transition metal oxide with rare earth or alkaline earth
  • Y10S505/779—Other rare earth, i.e. Sc,Y,Ce,Pr,Nd,Pm,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu and alkaline earth, i.e. Ca,Sr,Ba,Ra
  • Y10S505/78—Yttrium and barium-, e.g. YBa2Cu307
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/775—High tc, above 30 k, superconducting material
  • Y10S505/785—Composition containing superconducting material and diverse nonsuperconducting material

Definitions

• the present invention relates to a high-T superconductor, in particular a ceramic superconductor of a type which has at least one trivalent and one divalent element, another element, in particular one
• Transition metal element such as copper or niobium, and contains oxygen.
• Typical representatives of such ceramic high-T superconductors are e.g. B. by the general formulas NIE- _0, ME-R, 0 and M-.E, R_0 represent 3 2-y 2 x 2-y 3 x 2 3-y 2 x ⁇ tiert, whereby
• M at least one trivalent element, such as a lanthanoid element
• Bismuth, yttrium, E is at least one divalent element such as an alkaline earth element, and R is at least one transition element and x indicates the oxygen content.
• the transition element component R preferably consists entirely or at least partially of copper.
• 6.2 ⁇ x ⁇ 7.2 is preferably
• the invention further relates to a method for producing ceramic
• High-T superconductor materials It is particularly suitable for the production of high-T superconductors of the above type, but can be used in general c B. also on the system La-Si-b-0.
• high-T superconductor is to be understood here as superconductor materials whose transition temperature T is above 30 K.
• Types have a strongly anisotropic crystal structure and that their superconductor properties, such as the critical current density and the critical field strength, are strongly direction-dependent with respect to the crystal structure.
• Larger volumes of these ceramic superconductor materials can, however, only be produced economically in polycrystalline form according to the current state of the art and the individual crystal lites or grains of the poLyk ⁇ ' stalline material must then be aligned crystallographically in the same way if the optimum superconductor properties should be exploited.
• the known methods for producing structured or oriented polycrystalline ceramic high-T superconductor materials are complicated, time-consuming and not always reproducible. Single crystals from high T -
• the present invention is accordingly based on the object of specifying a polycrystalline high-T superconductor material with grains which are largely aligned graphically and / or with relatively large single crystals, and a simple and reproducible method for producing such a superconductor material.
• the starting materials yielding the desired superconductor material e.g. B. a compound of at least one trivalent element (typically lanthanide element, bismuth, yttrium), a compound of at least one divalent element (typically alkaline earth
• a reaction mixture which preferably contains the divalent element, such as the alkaline earth element, in a substoichiometric amount Contains 5 to 10% if necessary up to 15% below the stoichiometric amount.
• the foreign element compound which disappears as far as possible from the resulting superconductor material is in particular an inorganic metal compound, such as an alkali metal compound, e.g. B is an alkali metal oxide.
• the foreign element or elements can be contained in the reaction mixture in an amount which is approximately equal to or greater than the deficit of the divalent (and possibly trivalent) element.
• the molar amount of the foreign element e.g. B. the alkali metal, which is introduced in the form of a compound such as the oxide, can be up to ten times the molar deficit.
• the added material largely evaporates during reaction annealing or sintering, which is carried out at normal temperatures in air or oxygen, and only traces of the foreign element remain in the order of magnitude of ppm to a few parts per thousand based on the molar proportion of divalent element in the finished superconductor material back.
• the orientation effect could not be achieved simply by reducing the proportion of divalent and / or trivalent element in the starting material.
• the invention is particularly suitable for superconductors with a "YBaCu” or "123" structure, such as yttrium barium cuprate, wherein if the alkaline earth metal is barium, a potassium compound, such as potassium oxide or potassium carbonate, is preferably used as the removable or volatilizable compound.
• a potassium compound such as potassium oxide or potassium carbonate
• the invention can also be applied to ceramic superconductor materials with a different structure, e.g. B. of the type lanthanum strontium cuprate, W smutcalcium strontium cuprate, lanthanum strontium niobate and analogous compounds. If the superconductor material contains alkaline earth elements with a smaller ion radius than Ba, compounds of alkali metals with a smaller ion radius than potassium are preferably used as volatile compounds.
• the material obtained by reaction annealing in the manner described above is generally still somewhat porous.
• the material obtained in the reaction annealing is comminuted, e.g. B. in a mortar or ball mill, then pressed into shape and then sintered. This additional pressing and sintering process gives a practically completely dense material that is 95% or more oriented.
• the invention achieves some essential advantages over the prior art: Above all, moldings can be produced with grains that are largely aligned crystallographically perpendicular to the c-axis. A 100% alignment can be achieved within the accuracy of X-ray spectra.
• the method is also suitable for the formation of thin epitaxial layers made of high-T superconductor materials on suitable substrates.
• the process also enables relatively large single crystals to be produced, it is simple and takes relatively little time, and an aftertreatment, such as an annealing in oxygen, is not required.
• the material obtained after the first sintering has the formula
• the dense ceramic produced in the manner described above is also highly oriented (approx. 95%). Both the material obtained after the first sintering step and the dense ceramic are considerably more stable against environmental influences than corresponding known materials.
• the jump temperature T determined by conductivity measurements, at 94 K, is the same as that of the corresponding known material YBa_Cu, 0, Cj _; x> 0. J ⁇ , J + X
• a material with a slight deficiency in E and possibly M arises with unchanged penetration temperature, which is considerably more stable against external influences than corresponding known materials.
• a post-treatment in air or oxygen flow is not necessary.
• Example 1 The mixture is heated to 900 ° C and then immediately brought to 980 ° C-1000 ° C at 20 ° / h and held there for 24-48 h. Then the preparation is slowly cooled to 900 C (5-10 / h) and from there quickly (50 / h) to room temperature.
• the product is a solid, dense block consisting of large crystals (typically 2x3x1.5 mm).
• the tetragonal material becomes orthorhombic by post-oxidation (24-48 h: 600 C; 0 -, - atmosphere). It shows (also as a whole block) the M adoptednei effect in liquid nitrogen, also the suspension effect and has a transition temperature of 90 K.
• Rastei and polarization microscopic images show that the crystalline districts are home to microdomains. The individual mosaic domains are only slightly misfit with regard to orientation.
• the chemical analysis shows not only a Ba deficit, but also an yttrium excess: (Y n ,, Ba nr -, ) , Cu, 0, a . is a typ.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Inorganic Compounds Of Heavy Metals (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Oxygen, Ozone, And Oxides In General (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6348174

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (2)

Citations (2)

Family Cites Families (6)

• 1988
  • 1988-02-25 DE DE3805954A patent/DE3805954C1/de not_active Expired
• 1989
  • 1989-02-22 EP EP89902518A patent/EP0402371B1/de not_active Expired - Lifetime
  • 1989-02-22 DE DE58909256T patent/DE58909256D1/de not_active Expired - Fee Related
  • 1989-02-22 JP JP1502335A patent/JP2840349B2/ja not_active Expired - Fee Related
  • 1989-02-22 US US07/573,038 patent/US5413980A/en not_active Expired - Fee Related
  • 1989-02-22 WO PCT/EP1989/000163 patent/WO1989008330A1/de not_active Ceased

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events