WO1989007086A1 - SUPERCONDUCTING Bi-Sr-Ca-Cu OXIDE COMPOSITIONS AND PROCESS FOR MANUFACTURE - Google Patents
SUPERCONDUCTING Bi-Sr-Ca-Cu OXIDE COMPOSITIONS AND PROCESS FOR MANUFACTURE Download PDFInfo
- Publication number
- WO1989007086A1 WO1989007086A1 PCT/US1989/000354 US8900354W WO8907086A1 WO 1989007086 A1 WO1989007086 A1 WO 1989007086A1 US 8900354 W US8900354 W US 8900354W WO 8907086 A1 WO8907086 A1 WO 8907086A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- composition
- superconducting
- tube
- phase
- value
- Prior art date
Links
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 materials
- H10N60/857—Ceramic materials comprising copper oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/02—Oxides or hydroxides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G3/00—Compounds of copper
- C01G3/006—Compounds containing, besides copper, two or more other elements, with the exception of oxygen or hydrogen
-
- 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
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/64—Burning or sintering processes
- C04B35/645—Pressure sintering
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/76—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by a space-group or by other symmetry indications
-
- 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
- Y10S505/80—Material per se process of making same
- Y10S505/801—Composition
- Y10S505/809—Ceramic
-
- 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
- Y10S505/80—Material per se process of making same
- Y10S505/81—Compound
-
- 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
- Y10S505/80—Material per se process of making same
- Y10S505/815—Process of making per se
Definitions
- This invention relates to novel sodium-containing lanthanum, copper oxide compositions which are superconducting and to a process for making them.
- the superconducting phase has been identified as the composition La 1 _ ⁇ (Ba,S ,Ca) x 0 4 _ with the tetragonal K 2 NiF 4 -type structure and with x typically about 0.15 and y indicating oxygen vacancies.
- This invention provides novel superconducting compositions having a phase with the formula La 2, - XNaXCuOz where x is from about 0.1 to about 0.3 and z is from about 3.8 to about 4.2; said composition having a superconducting transition temperature above 10 K.
- This invention also provides a process for making these compositions, said process consisting essentially of heating a mixture of stoichiometric quantities of La 2 0 3 , Na 2 0 2 and CuO in a sealed metal container at about 850°C to about 900°C for about 12 to about 24 hours.
- a sealed metal container is subjected to external pressure, typically of the order of 3 kbar (100 MPa) since it results in compositions having superconducting transition temperatures of 20 K or higher.
- the superconducting phase of the composition of this invention has the nominal formula La, 2 - XNaXCuOz ,' wherein x is from about 0.1 to about 0.3, and wherein the phase has the tetragonal K 2 NiF 4 -type structure with the 14/mmm space group as determined by X-ray powder diffraction measurements.
- the superconducting composition of the invention can be prepared by the following process: Stoichiometric quantities of La 2 0 3 , Na 2 0 2 and CuO are mixed, for example, by grinding them together in a mortar and heating them in a controlled atmosphere. It has been found that the composition of this invention is produced only when the atmosphere in which the reactants are heated is carefully controlled.
- One way to accomplish this controlled atmosphere is to place the reactants in a tube made of a non-reacting metal such as gold and then sealing the tube by welding.
- the sealed tube is then placed in a furnace and heated at about 850°C to about 900°C for about 12 to 24 hours.
- the power to the furnace is then turned off and the tube is furnace-cooled to 100°C and then removed from the furnace and quenched to ambient temperature.
- the tube is then opened and the black powder product recovered.
- Compositions prepared in this manner have superconducting transition temperatures from about 10 K to about 15 K.
- compositions prepared in this manner have superconducting transition temperatures exceeding 15 K, typically in the range of about 20 K to about 30 K.
- the product of the process of the invention is a single phase and is the composition of the invention.
- the relative amounts of reactants are chosen such that x appreciably exceeds 0.3, e.g., such that x « 0.4, the product is not a single phase but is a mixture comprised of the composition of the invention and other phases.
- Superconductivity can be confirmed by observing magnetic flux exclusion, i. e., the Meissner effect. This effect can be measured by the method described in an article by E. Polturak and B. Fisher in Physical Review B, 36, 5586(1987).
- the superconducting compositions of this invention can be used to conduct current extremely efficiently or to provide a magnetic field for magnetic imaging for medical purposes.
- a temperature below the superconducting transition temperature e.g., at or below about 30 K, preferably at or below about 10 K
- the wire mentioned previously could be wound to form a coil which would be exposed to liquid helium before inducing any current into the coil.
- EXAMPLE 1 2.9323 g of La 2 0 3 , 0.0780 g of Na 2 0 2 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was then heated to 850°C for 12 hours in a furnace. The tube was cooled to 100°C in the furnace, then removed from the furnace and quenched to room temperature. The tube was cut open and the black powder product was recovered.
- Meissner effect measurements showed that the compound is a superconductor with a transition temperature, T , of about 15 K.
- the X-ray powder diffraction pattern of the product is essentially the same as that shown in Table I and indicates that the La ⁇ 7 Na 0 3 CuO z product is a single phase and has tetragonal symmetry with the K 2 NiF 4 -type structure.
- Meissner effect measurements of the powder showed a superconducting phase transition of about 12 K.
- EXAMPLE 3 2.6065 g of La 2 0 3 , 0.1560 g of Na 2 0 2 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was then heated to 850°C for 12 hours in an autoclave. The tube was cooled in the autoclave to 100°C, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered.
- the results of an X-ray powder diffraction pattern of the product indicate that the product is a mixture of a tetragonal K 2 NiF 4 -type phase having essentially the same powder diffraction pattern as that shown in Table I and NaCu0 2 .
- Meissner effect measurements of the powder showed a superconducting phase transition of about 12 K.
- EXAMPLE 5 2.4436 g of La 2 0 3 , 0.1950 g of Na 2 0 2 and 0.7955 g of CuO were ground together in an agate mortar for 30 min inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was subjected to an external pressure of 3 kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product indicates that the product is a mixture of a tetragonal K 2 NiF 4 -type phase having essentially the same powder diffraction pattern as that shown in Table I and NaCu0 2 .
- Meissner effect measurements of the powder showed a superconducting phase transition at about 30 K.
- EXAMPLE 6 2.6065 g of La 2 0 3 , 0.1560 g of Na 2 0 2 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was subjected to an external pressure of 3kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product indicates that the product is a mixture of a tetragonal K 2 NiF 4 -type phase having essentially the same powder diffraction pattern as that shown in Table I and NaCu0 2 .
- Meissner effect measurements of the powder showed a superconducing phase transition at about 30 K.
- EXAMPLE 7 2.9323 g of La 2 0 3 , 0.0780 g of Na 2 0 2 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube sealed by welding it. The tube was subjected to an external pressure of 3kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered.
- 3kbar 100 MPa
- the X-ray powder diffraction pattern of the product is essentilly the same as that shown in Table I and indicates that the La ⁇ 8 Na 0 2 CuO z product is a single phase and has tetragonal symmetry with the K 2 NiF 4 -type structure.
- Meissner effect showed the compound is a superconductor with a transition temperature of about 20 K.
Abstract
Compositions containing a phase having the formula LA2-x?Nax?CuOz, wherein x is about 0.1 to about 0.3 and z is about 3.8 to about 4.2 are superconducting. Processes for manufacturing such compositions and for using them are disclosed.
Description
TITLE
SUPERCONDUCTING Bi-Sr-Ca-Cu OXIDE COMPOSITIONS AND PROCESS FOR MANUFACTURE
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to novel sodium-containing lanthanum, copper oxide compositions which are superconducting and to a process for making them. References
Bednorz and Muller, Z. Phys. B64, 189 (1986), disclose a superconducting phase in the La-Ba-Cu-0 system with a superconducting transition temperature of about 35 K. This disclosure was subsequently confirmed by a number of investigators [see, for example, Rao and Ganguly, Current Science, 56, 47 (1987), Chu et al.. Science 235, 567 (1987), Chu et al., Phys. Rev. Lett. 58, 405 (1987), Cava et al., Phys. Rev. Lett. 58, 408 (1987), Bednorz et al. , Europhys. Lett. 3, 379 (1987)]. The superconducting phase has been identified as the composition La1_χ (Ba,S ,Ca)x04_ with the tetragonal K2NiF4-type structure and with x typically about 0.15 and y indicating oxygen vacancies.
Over 400 scientific papers have appeared covering various aspects of these materials. Only three papers discuss attempts to incorporate an alkali metal into the structure and all three have used potassium. Ogita et al., Japn. J. Appl. Phys. 26, L415 (1987) disclose the preparation of (La0 g5K0 05)2CuO4_ by mixing prescribed amounts of La203, CuO and K2C03 , preheating the mixture at 700°C in air for 12 hours and sintering at 1000°C in air for 2 hours. The (La0 _ g5K0 > 05 )2Cu04
product was found to be of the orthorhombic K2NiF4 type structure and was a semiconductor and not a superconductor down to liquid helium temperature.
Fine et al., "Chemistry of High-Temperature Superconductors", ACS Symposium Series 351, Edited by D. L. Nelson, M. S. hittingham and T. F. George, American Chemical Society, Wash., D. C. (1987), Chapter 10, discuss the results of a study on the effect of nominal composition on superconductivity in La2Cu04 . They mixed the oxides of La203 and CuO in appropriate amounts to form samples of the with nominal stoichiometries La2Cu04_ and Laχ gCu04_ respectively. Each mixture of starting materials was divided into three portions and 5% K2 C0 3 anc 10% K2C03 were added to the second and third portions of each mixture. A sample of nominal composition Laχ 9KQ jCuO., was also prepared from appropriate amounts of La203 , CuO, and K2C03. The x-ray powder diffraction data indicated that all compositions were single phase or nearly single phase and the authors suggested that either the K20 sublimed out of the sample or was present in a poorly crystalline form. The lattice parameters calculated for all seven samples were the same within two standard deviations and were consistent with the published values for the lattice p rarameters for La 2,CuO4.-y . The authors state that the implications are "that in all cases the bulk of the sample is stoichiometric, La2Cu04 , and that a solid solution of the type La2_χKχCu04 did not form".
Fine et al., Phys. Rev. B 36, 5716 (1987), report on the same study discussed in their ACS Symposium Series 351 chapter along with
data on an eighth sample of nominal composition Laj^ 8Cu04_ and state the same conclusions.
There is no disclosure that substitution of any alkali metal into La2Cu04 will result in a single phase composition exhibiting superconductivity above liquid helium temperatures and no disclosure of a composition of the formula La2_χAχCu04_ where A is an alkali metal other than potassium.
SUMMARY OF THE INVENTION
This invention provides novel superconducting compositions having a phase with the formula La 2, - XNaXCuOz where x is from about 0.1 to about 0.3 and z is from about 3.8 to about 4.2; said composition having a superconducting transition temperature above 10 K.
This invention also provides a process for making these compositions, said process consisting essentially of heating a mixture of stoichiometric quantities of La203, Na202 and CuO in a sealed metal container at about 850°C to about 900°C for about 12 to about 24 hours. Preferred is the process in which the sealed metal container is subjected to external pressure, typically of the order of 3 kbar (100 MPa) since it results in compositions having superconducting transition temperatures of 20 K or higher.
DETAILED DESCRIPTION OF THE INVENTION
The superconducting phase of the composition of this invention has the nominal formula La, 2 - XNaXCuOz ,' wherein x is from about 0.1 to about 0.3, and wherein the phase has the tetragonal K2NiF4-type structure with the 14/mmm
space group as determined by X-ray powder diffraction measurements.
The superconducting composition of the invention can be prepared by the following process: Stoichiometric quantities of La203, Na202 and CuO are mixed, for example, by grinding them together in a mortar and heating them in a controlled atmosphere. It has been found that the composition of this invention is produced only when the atmosphere in which the reactants are heated is carefully controlled. One way to accomplish this controlled atmosphere is to place the reactants in a tube made of a non-reacting metal such as gold and then sealing the tube by welding. The sealed tube is then placed in a furnace and heated at about 850°C to about 900°C for about 12 to 24 hours. The power to the furnace is then turned off and the tube is furnace-cooled to 100°C and then removed from the furnace and quenched to ambient temperature. The tube is then opened and the black powder product recovered. Compositions prepared in this manner have superconducting transition temperatures from about 10 K to about 15 K.
Preferred is the process in which the sealed container is subjected to external pressure, typically of the order of 3 kbar (100 MPa) before the heating commences and during the heating step. The compositions prepared in this manner have superconducting transition temperatures exceeding 15 K, typically in the range of about 20 K to about 30 K.
When the relative amounts of reactants are chosen consistent with the formula La 2,- XNaXCuOz ,' wherein x is from about 0.1 to about
0.3 and z is from about 3.8 to about 4.2, the
product of the process of the invention is a single phase and is the composition of the invention. When the relative amounts of reactants are chosen such that x appreciably exceeds 0.3, e.g., such that x « 0.4, the product is not a single phase but is a mixture comprised of the composition of the invention and other phases.
Superconductivity can be confirmed by observing magnetic flux exclusion, i. e., the Meissner effect. This effect can be measured by the method described in an article by E. Polturak and B. Fisher in Physical Review B, 36, 5586(1987).
The superconducting compositions of this invention can be used to conduct current extremely efficiently or to provide a magnetic field for magnetic imaging for medical purposes. Thus, by cooling the composition in the form of a wire or bar to a temperature below the superconducting transition temperature, e.g., at or below about 30 K, preferably at or below about 10 K, by exposing the material to liquid helium in a manner well known to those in this field; and initiating a flow of electrical current, one can obtain such flow without any electrical resistive losses. To provide exceptionally high magnetic fields with minimal power losses, the wire mentioned previously could be wound to form a coil which would be exposed to liquid helium before inducing any current into the coil.
EXAMPLES OF THE INVENTION
EXAMPLE 1 2.9323 g of La203 , 0.0780 g of Na202 and 0.7955 g CuO were ground together in an agate
mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was then heated to 850°C for 12 hours in a furnace. The tube was cooled to 100°C in the furnace, then removed from the furnace and quenched to room temperature. The tube was cut open and the black powder product was recovered. The results of an X-ray powder diffraction pattern of the product indicate that the L j 8Na0 2CuOz product has tetragonal symmetry with a K2NiF4-type structure. No other phase was detected. The d-spacings, the relative intensities and the indices of the observed reflections are shown in Table I.
Meissner effect measurements showed that the compound is a superconductor with a transition temperature, T , of about 15 K.
hkl 101 004 103 110 006 105 114 200 116 107 211 008 204
213
EXAMPLE 2 2.7694 g of La203 , 0.1170 g of Na202 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was then heated to 850°C for 12 hours in a furnace. The tube was cooled to 100°C in the furnace, then removed from the furnace and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product is essentially the same as that shown in Table I and indicates that the Laχ 7Na0 3 CuOz product is a single phase and has tetragonal symmetry with the K2NiF4-type structure.
Meissner effect measurements of the powder showed a superconducting phase transition of about 12 K.
EXAMPLE 3 2.6065 g of La203, 0.1560 g of Na202 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was then heated to 850°C for 12 hours in an autoclave. The tube was cooled in the autoclave to 100°C, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The results of an X-ray powder diffraction pattern of the product indicate that the product is a mixture of a tetragonal K2NiF4-type phase having essentially the same
powder diffraction pattern as that shown in Table I and NaCu02.
Meissner effect measurements of the powder showed a superconducting phase transition of about 12 K.
EXAMPLE 4
2.7694 g of La203 , 0.1170 g of Na202 and 0.7955 g of CuO were ground together in an agate mortar for 30 min inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was subjected to an external pressure of 3 kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product is essentially the same as that shown in Table I and indicates that the La. ,Nan , CuO product is a single phase and has tetragonal symmetry with K2NiF4-type structure.
Meissner effect measurements showed the compound is a superconductor with a transition temperature, Tc , of about 30 K.
EXAMPLE 5 2.4436 g of La203 , 0.1950 g of Na202 and 0.7955 g of CuO were ground together in an agate mortar for 30 min inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was subjected to an external pressure of 3 kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in
the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product indicates that the product is a mixture of a tetragonal K2NiF4-type phase having essentially the same powder diffraction pattern as that shown in Table I and NaCu02.
Meissner effect measurements of the powder showed a superconducting phase transition at about 30 K.
EXAMPLE 6 2.6065 g of La203 , 0.1560 g of Na202 and 0.7955 g CuO were ground together in an agate mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube was sealed by welding it. The tube was subjected to an external pressure of 3kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product indicates that the product is a mixture of a tetragonal K2NiF4-type phase having essentially the same powder diffraction pattern as that shown in Table I and NaCu02.
Meissner effect measurements of the powder showed a superconducing phase transition at about 30 K.
EXAMPLE 7 2.9323 g of La203 , 0.0780 g of Na202 and 0.7955 g CuO were ground together in an agate
mortar for 30 min. inside a dry box. The resulting powder was loaded in a gold tube (3/8" dia and 5" length) and the tube sealed by welding it. The tube was subjected to an external pressure of 3kbar (100 MPa) and heated to 900°C for 12 hours in an autoclave. The tube was cooled to 100°C in the autoclave, then removed from the autoclave and quenched to room temperature. The tube was cut open and the black powder product was recovered. The X-ray powder diffraction pattern of the product is essentilly the same as that shown in Table I and indicates that the Laχ 8Na0 2CuOz product is a single phase and has tetragonal symmetry with the K2NiF4-type structure.
Meissner effect showed the compound is a superconductor with a transition temperature of about 20 K.
Claims
1. A superconducting composition containing a metal oxide phase of the formula La2_χNaχCuOz wherein x is a value from about 0.1 to about 0.3; z is a value from about 3.8 to about 4.2; and said phase has the tetragonal K2NiF4-type structure containing the 14/mmm space group as determined by X-ray powder diffraction measurements, said composition having a superconducting transition temperature above 10K.
2. A superconducting composition as in Claim 1 wherein z has a value of about 4.
3. A process for making superconducting compositions consisting essentially of mixing stoichiometric quantities of La203 , Na202 and Cu; heating said mixture in a sealed container at about 850°C to about 900°C for about 12 to about 24 hours to form an oxide composition; furnance-cooling said composition to about 100°C; and thereafter quenching said composition at ambient temperature.
4. A process as in Claim 3 wherein said sealed container while being heated is subjected to an external pressure of about 3 kbar.
5. A method for conducting an electrical current within a conductor material without electrical resistive losses comprising the steps of: cooling a conductor material composed of a composition containing a metal oxide phase of the formula La2_xNaχCuOz wherein x is a value from about 0.1 to about 0.3; z is a value from about 3.8 to about 4.2; and said phase has the tetragonal K2NiF4-type structure containing the 14/mmm space group as determined by X-ray powder diffractive measurements, to a temperature at or below about 10K; initiating a flow of electrical current within said conductor material while maintaining said material at or below 10K at which said material becomes superconductive.
6. A method as in Claim 5 wherein said conductor material is cooled to a temperature at or below about 30 K.
7. A method as in Claim 5 wherein said conductor material is in the form of a coiled wire.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1019890701818A KR900700389A (en) | 1988-02-04 | 1989-02-03 | Superconducting Bi-Sr-Ca-Cu oxide composition and its preparation method |
NO90903159A NO903159L (en) | 1988-02-04 | 1990-07-13 | SUPERLY METAL OXIDE MATERIALS AND MANUFACTURING PROCESS |
DK177290A DK177290D0 (en) | 1988-02-04 | 1990-07-25 | SUPER CONDUCTIVE MATERIAL, ITS MANUFACTURING AND USE |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/152,185 US4835136A (en) | 1988-02-04 | 1988-02-04 | Lanthanum: sodium copper superconducting metal oxide compositions and process for manufacture |
US152,185 | 1988-02-04 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1989007086A1 true WO1989007086A1 (en) | 1989-08-10 |
Family
ID=22541851
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1989/000354 WO1989007086A1 (en) | 1988-02-04 | 1989-02-03 | SUPERCONDUCTING Bi-Sr-Ca-Cu OXIDE COMPOSITIONS AND PROCESS FOR MANUFACTURE |
Country Status (8)
Country | Link |
---|---|
US (1) | US4835136A (en) |
EP (1) | EP0398988A1 (en) |
JP (1) | JPH03502445A (en) |
KR (1) | KR900700389A (en) |
AU (1) | AU3184889A (en) |
DK (1) | DK177290D0 (en) |
HU (1) | HUT55319A (en) |
WO (1) | WO1989007086A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0457654A1 (en) * | 1990-05-18 | 1991-11-21 | Rhone-Poulenc Chimie | Method for preparation of a superconducting composition based on yttrium or a rare earth, an alkaline-earth metal, copper and oxygen |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69516526T2 (en) * | 1995-12-28 | 2000-11-23 | Ngk Insulators Ltd | Porous sintered lanthanum manganite bodies and process for their manufacture |
-
1988
- 1988-02-04 US US07/152,185 patent/US4835136A/en not_active Expired - Fee Related
-
1989
- 1989-02-03 AU AU31848/89A patent/AU3184889A/en not_active Abandoned
- 1989-02-03 WO PCT/US1989/000354 patent/WO1989007086A1/en not_active Application Discontinuation
- 1989-02-03 KR KR1019890701818A patent/KR900700389A/en not_active Application Discontinuation
- 1989-02-03 EP EP19890902680 patent/EP0398988A1/en not_active Withdrawn
- 1989-02-03 HU HU891426A patent/HUT55319A/en unknown
- 1989-02-03 JP JP1502493A patent/JPH03502445A/en active Pending
-
1990
- 1990-07-25 DK DK177290A patent/DK177290D0/en not_active Application Discontinuation
Non-Patent Citations (10)
Title |
---|
Chem & Eng. News, published, 01 February 1988, R. Dagani 'New Class of Superconductors Discovered', see page 5. * |
Jpn. J. Appl. Phys., Vol. 27, No. 2, published February 1988, H. MAEDA et al., 'A New High-Tc... Element, see pages l209-l210. * |
Jpn. J. Appl. Phys., Vol. 27, No. 3 published March 1988, 'Identification of... Bi-Ca-Sr-Cu-O System', E. TAKAYAMA-MUROMACHI et al., see pages l365-l368. * |
Jpn. J. Appl. Phys., Vol. 27, No. 3, published March 1988, T. KIJIMA et al., 'Identification of... Bi-Ca-Sr-Cu-O System', see pages l369-l371 * |
Jpn. J. Appl. Phys., Vol. 27, No. 3, published March 1988, Y. BANDO et al., 'Structure... Electron Microsopy', see pages l358-l360. * |
Jpn. J. Appl. Phys., Vol. 27, No. 3, published March 1988, Y. MATSUI et al., 'High-Resolution... Bi-Sr-Ca-Cu-O System', see pages l361-l364. * |
Jpn. J. Appl. Phys., Vol. 27, No. 3, published March 1988, Y. MATSUI et al., 'Possible Model... Microscopy', see pages l372-l375. * |
Phys. Rev. Lett., Vol. 60, No. 10, published 07 March 1988, C.W. CHU et al., 'Superconductivity up to 114K... Elements', see pages 941-943. * |
Phys. Rev. Lett., Vol. 60, No. 12, published 21 March 1988, R.M. HAZEN et al., 'Superconductivity... Phase Identification, see pages 1174-1177. * |
Z. Phys. B., Vol. 68, published 1987, C. MICHEL et al. 'Superconductivity in the Bi-Sr-Ca-Cu-O System', see pages 421-423. * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0457654A1 (en) * | 1990-05-18 | 1991-11-21 | Rhone-Poulenc Chimie | Method for preparation of a superconducting composition based on yttrium or a rare earth, an alkaline-earth metal, copper and oxygen |
FR2662157A1 (en) * | 1990-05-18 | 1991-11-22 | Rhone Poulenc Chimie | PROCESS FOR THE PREPARATION OF A SUPERCONDUCTING COMPOSITION BASED ON YTTRIUM OR RARE EARTH, ALKALINE EARTH, COPPER AND OXYGEN |
Also Published As
Publication number | Publication date |
---|---|
DK177290A (en) | 1990-07-25 |
KR900700389A (en) | 1990-08-13 |
EP0398988A1 (en) | 1990-11-28 |
JPH03502445A (en) | 1991-06-06 |
DK177290D0 (en) | 1990-07-25 |
US4835136A (en) | 1989-05-30 |
HUT55319A (en) | 1991-05-28 |
AU3184889A (en) | 1989-08-25 |
HU891426D0 (en) | 1991-03-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4894361A (en) | Superconducting metal oxide Tl-Pb-Ca-Sr-O compositions and processes for manufacture and use | |
US4929594A (en) | Superconducting composition Tl2 Ba2 CuO6+x and process for manufacture | |
US5126316A (en) | Bi2 Sr3-x Yx Cu2 O8+y superconducting metal oxide compositions | |
US5017554A (en) | Superconducting metal oxide Tl-Pb-Ca-Sr-Cu-O compositions and processes for manufacture and use | |
US5389603A (en) | Oxide superconductors, and devices and systems comprising such a superconductor | |
US5264414A (en) | Superconducting metal oxide (Tl,Bi)1 Sr2 Ca2 Cu3 O.sub.y | |
US6855670B1 (en) | Superconducting bismuth-strontium-calcium-copper oxide compositions and process for manufacture | |
US4835136A (en) | Lanthanum: sodium copper superconducting metal oxide compositions and process for manufacture | |
EP0489087B1 (en) | Superconducting metal oxide compositions and processes for manufacture and use | |
US5219833A (en) | Process for manufacturing single phase Tl2 Ba2 CuO6-x superconductors | |
EP0428630B1 (en) | Superconducting metal oxide compositions and processes for manufacture and use | |
EP0441893B1 (en) | Superconducting metal oxide compositions and processes for manufacture and use | |
EP0441903A4 (en) | Superconducting metal oxide compositions and processes for manufacture and use | |
Subramanian et al. | Superconducting metal oxide (Tl, Bi) 1 Sr 2 Ca 2 Cu 3 O y | |
JPH0465395A (en) | Superconducting fibrous crystal and its production | |
JPH0597435A (en) | Metal oxide material | |
JPH09502959A (en) | Superconductor containing at least one of barium and strontium and thallium, copper, oxygen and fluorine | |
WO1991011391A1 (en) | Superconducting metal oxyde compositions |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AU DK HU JP KR NO SU |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE FR GB IT LU NL SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1989902680 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1989902680 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1989902680 Country of ref document: EP |