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US4897378A
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Preparation of thin film superconducting oxides
Assignee: Massachusetts Institute of Technology
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Filing: 1987-11-23
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Granted: 1990-01-30
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Expires: 2007-11-23
Abstract
Abstract Cations such as La, Sr, Cu, or Y, Ba, Cu are dissolved in an organic solvent such as ethylene glycol and citric acid. The solution is formed into either a free-standing or supported film which is dried to produce a solid organic polymer. The polymer is then fired in an oxidizing atmosphere (pyrolysis) to obtain the superconducting oxide. It is preferred that the film be spin coated on a substrate to produce uniform coatings of thicknesses less than one micrometer. The resulting superconducting oxide film is fully dense, of controlled microstructure, very homogeneous in composition and suitable for demanding electronic device purposes or as coatings to form superconducting wires or other current carrying components.
Inventors
- 👤 Yet-Ming Chiang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:16
CPC Classifications
H; H01; H01B; H01B12/00; H01B12/02; H01B12/06; C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0324; H10N60/0576; H10N60/0604; H10N60/20; H10N60/203
Claims Analysis
Total Claims: 70
Claim 1
Independent Claim
92 words
A method of preparing a copper oxide-based superconducting oxide/noble metal composite film comprising the steps of: making an organic liquid solution of the cation constituents of the oxide film by chelating a precursor solution containing said cation constituents with an organic acid and adding a polymerizing alcohol; adding a noble metal to said organic liquid solution; forming the solution into a liquid film; drying and heating the liquid film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the copper oxide-based superconducting oxide/noble metal composite film.
Claim 2
Independent Claim
92 words
A method of preparing a copper oxide-based superconducting oxide/noble metal composite film comprising the steps of: making an organic liquid solution of the cation constituents of the oxide film by chelating a precursor solution containing said cation constituents with an organic acid and adding a polymerizing alcohol; adding a noble metal to said organic liquid solution; forming the solution into a liquid film; drying and heating the liquid film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the copper oxide-based superconducting oxide/noble metal composite film.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein the film is free-standing.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the film is supported on a flat substrate.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the film is supported on a ribbon, wire, coil or other three-dimensional substrate.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the film thickness is less than one micrometer.
Claim 7
Dependent Claim
10 words
The method of claim 1 wherein the film is dense.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein the film is porous.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein multiple coatings are used to form thicker or more dense solid superconducting film.
Claim 10
Dependent Claim
13 words
The method of claim 2 wherein a supporting framework supports the superconducting film.
Claim 11
Dependent Claim
15 words
The method of claim 9 wherein the supporting framework is a wire frame or mesh.
Claim 12
Dependent Claim
22 words
The method of claim 10 wherein the wire frame or mesh is dipped into the organic liquid solution to form the film.
Claim 13
Dependent Claim
20 words
The method of claim 2 wherein the liquid film is spread on a substrate, dried, and separated from the substrate.
Claim 14
Dependent Claim
15 words
The method of claim 3 or 4 wherein the substrate is a single crystalline material.
Claim 15
Dependent Claim
22 words
The method of claim 3 or 4 wherein the substrate is dipped into the organic liquid solution to form a liquid film.
Claim 16
Dependent Claim
16 words
The method of claim 3 wherein the organic liquid solution is applied to a spinning substrate.
Claim 17
Dependent Claim
20 words
The method of claim 3 or 4 wherein the substrate is wet or partially wet by the organic liquid solution.
Claim 18
Dependent Claim
60 words
The method of claim 3, 4, 13, 14, 15, or 16 wherein the substrate is chosen from the group consisting of SiO 2 , SiC, Si, SrTiO 3 , BaTiO 3 , MgO, ZrO 2 , carbon coated with SiC, Al 2 O 3 , stainless steel, copper alloys, nickel alloys, cobalt alloys, gold alloys, platinum alloys and tantalum alloys.
Claim 19
Dependent Claim
14 words
The method of claim 15 wherein the film is dried by spinning in air.
Claim 20
Dependent Claim
18 words
The method of claim 15 wherein the film is dried by heating the substrate and film while spinning.
Claim 21
Dependent Claim
18 words
The method of claim 15 wherein the film is dried by heating the substrate and film after spinning.
Claim 22
Dependent Claim
35 words
The method of claim 1 wherein the cations are chosen from the group consisting of La, Ba, Cu, Y, Sr, Ca, and rare-earth ions such as Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.
Claim 23
Dependent Claim
23 words
The method of claim 1 wherein the oxide film comprises La 2-x M x CuO 4-y where M is an alkaline earth cation.
Claim 24
Dependent Claim
36 words
The method of claim 1 wherein the oxide film comprises NBa 2 Cu 3 O 7-x where N is Y, or a rare-earth ion such as La, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.
Claim 25
Dependent Claim
16 words
The method of claim 1 wherein the organic liquid solution includes ethylene glycol and citric acid.
Claim 26
Dependent Claim
46 words
The method of claim 1 wherein the cation constituents are introduced as compounds chosen from the group consisting of La 2 O 3 , CuO, Y 2 O 3 , SrCo 3 , Cu(OH) 2 , CuCO 3 , BaCO 3 , And Cu 2 O.
Claim 27
Dependent Claim
21 words
The method of claim 20 wherein the liquid film solution is dried at a temperature in the range of 100°-200° C.
Claim 28
Dependent Claim
16 words
The method of claim 1 wherein the solid organic polymer is fired in an oxidizing atmosphere.
Claim 29
Dependent Claim
21 words
A superconducting oxide film prepared according to the method of claim 1, 3, 4, 13, 21, 22, 23, 24, or 25.
Claim 30
Dependent Claim
13 words
The method of claim 1 wherein the cations comprise La, Sr, and Cu.
Claim 31
Dependent Claim
19 words
The method of claim 1 wherein the oxide film comprises La 1 .825 Sr 0 .175 CuO 4-x .
Claim 32
Dependent Claim
13 words
The method of claim 1 wherein the cations comprise Y, Ba and Cu.
Claim 33
Dependent Claim
17 words
The method of claim 1 wherein the oxide film comprises YBa 2 Cu 3 O 7-x .
Claim 34
Dependent Claim
12 words
The method of claim 1 wherein the organic acid is citric acid.
Claim 35
Dependent Claim
12 words
The method of claim 1 wherein the organic acid is lactic acid.
Claim 36
Dependent Claim
12 words
The method of claim 1 wherein the organic acid is glycolic acid.
Claim 37
Dependent Claim
11 words
The method of claim 1 wherein the alcohol is ethylene glycol.
Claim 38
Dependent Claim
10 words
The method of claim 1 wherein the alcohol is glycerol.
Claim 39
Dependent Claim
24 words
The method of claim 29 wherein the polymer is fired for approximately one-half hour at approximately 800° C. and then cooled to room temperature.
Claim 40
Dependent Claim
24 words
The method of claim 31 wherein the polymer is fired for approximately one-half hour at approximately 900° C. and then cooled to room temperature.
Claim 41
Dependent Claim
23 words
The method of claim 3 wherein the substrate is a single crystalline material for inducing a preferred crystalline orientation in the thin film.
Claim 42
Dependent Claim
93 words
The method of claim 6 further comprising: making an organic liquid solution of the cation constituents of a second superconducting oxide/noble metal composite layer by chelating a cation constituent precursor solution with an organic acid and adding a polymerizing alcohol; forming the solution into a liquid film on the first superconducting oxide/noble metal composite layer; drying and heating the liquid film solution to obtain a second solid organic polymer or resin; firing the second polymer to obtain a second superconducting oxide/noble metal comprising layer; and repeating the process for additional superconducting oxide layers.
Claim 43
Dependent Claim
179 words
Method of preparing a copper oxide-based superconducting oxide/noble metal composite film on a blocking or adhesion promoting layer supported on a substrate comprising: making an organic liquid solution of the constituents of the blocking or adhesion promoting layer by chelating a precursor solution containing the constituents of the blocking or adhesion layer with an organic acid and adding a polymerizing alcohol; forming this liquid into a film on the substrate; drying and heating the liquid film to obtain a solid organic polymer; firing the polymer to obtain the barrier or adhesion promoting layer; making an organic liquid solution of the cation constituents of the superconducting oxide/noble metal composite film by chelating a precursor solution containing the cation constituents of the oxide with an organic acid and adding a polymerizing alcohol; forming the solution into a liquid film on the blocking or adhesion promoting layer; drying and heating the liquid superconducting oxide film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the superconducting/noble metal composite layer on the blocking or adhesion promoting layer.
Claim 44
Dependent Claim
179 words
Method of preparing a copper oxide-based superconducting oxide/noble metal composite film on a blocking or adhesion promoting layer supported on a substrate comprising: making an organic liquid solution of the constituents of the blocking or adhesion promoting layer by chelating a precursor solution containing the constituents of the blocking or adhesion layer with an organic acid and adding a polymerizing alcohol; forming this liquid into a film on the substrate; drying and heating the liquid film to obtain a solid organic polymer; firing the polymer to obtain the barrier or adhesion promoting layer; making an organic liquid solution of the cation constituents of the superconducting oxide/noble metal composite film by chelating a precursor solution containing the cation constituents of the oxide with an organic acid and adding a polymerizing alcohol; forming the solution into a liquid film on the blocking or adhesion promoting layer; drying and heating the liquid superconducting oxide film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the superconducting/noble metal composite layer on the blocking or adhesion promoting layer.
Claim 45
Dependent Claim
14 words
The method of claim 42 wherein the barrier or adhesion promoting layer is non-superconducting.
Claim 46
Dependent Claim
21 words
The method of claim 42 further including alternating layers of the barrier or adhesion promoting layer and the superconducting oxide layer.
Claim 47
Dependent Claim
19 words
The method of claim 42 wherein the barrier or adhesion promoting layer is the non-superconducting oxide SrTiO 3 .
Claim 48
Dependent Claim
19 words
The method of claim 42 wherein the barrier or adhesion promoting layer is the non-superconducting oxide BaTiO 3 .
Claim 49
Dependent Claim
19 words
The method of claim 42 wherein the barrier or adhesion promoting layer is the non=superconducting oxide ZrO 2 .
Claim 50
Dependent Claim
15 words
The method of claim 1 wherein the noble metal is added as an oxide precursor.
Claim 51
Dependent Claim
14 words
The method of claim 1 wherein the metal is added as a carbonate precursor.
Claim 52
Dependent Claim
15 words
The method of claim 1 wherein the noble metal is added as an hydroxide precursor.
Claim 53
Dependent Claim
15 words
The method of claim 1 wherein the noble metal is added as an acetate precursor.
Claim 54
Dependent Claim
16 words
The method of claim 1 wherein the noble metal precursor is added as a citrate precursor.
Claim 55
Dependent Claim
18 words
The method of claim 1 wherein the noble metal is added in the form of a fine powder.
Claim 56
Dependent Claim
18 words
The method of claim 1 wherein the noble metal is added in the form of a colloidal suspension.
Claim 57
Dependent Claim
11 words
The method of claim 1 wherein the noble metal is gold.
Claim 58
Dependent Claim
11 words
The method of claim 1 wherein the noble metal is silver.
Claim 59
Dependent Claim
11 words
The method of claim 1 wherein the noble metal is platinum.
Claim 60
Dependent Claim
11 words
The method of claim 1 wherein the noble metal is irridium.
Claim 61
Dependent Claim
11 words
The method of claim 1 wherein the noble metal is rhodium.
Claim 62
Independent Claim
113 words
A method of preparing a copper oxide-based superconducting oxide/noble method composite film on a noble metal layer supported on a substrate comprising: depositing a noble metal on a substrate: making an organic liquid solution of the cation constituents of the oxide film by chelating a precursor solution containing said cation constituents with an organic acid and adding a polymerizing alcohol; adding a noble metal to the organic liquid solution; forming the solution into a liquid film on the noble metal layer; drying and heating the liquid film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the superconducting oxide/noble metal composite layer on the noble metal layer.
Claim 63
Independent Claim
113 words
A method of preparing a copper oxide-based superconducting oxide/noble method composite film on a noble metal layer supported on a substrate comprising: depositing a noble metal on a substrate: making an organic liquid solution of the cation constituents of the oxide film by chelating a precursor solution containing said cation constituents with an organic acid and adding a polymerizing alcohol; adding a noble metal to the organic liquid solution; forming the solution into a liquid film on the noble metal layer; drying and heating the liquid film solution to obtain a solid organic polymer or resin; and firing the polymer to obtain the superconducting oxide/noble metal composite layer on the noble metal layer.
Claim 64
Dependent Claim
13 words
The method of claim 60 wherein the noble metal is deposited by sputtering.
Claim 65
Dependent Claim
13 words
The method of claim 60 wherein the noble metal is deposited by evaporation.
Claim 66
Dependent Claim
11 words
The method of claim 60 wherein the noble metal is gold.
Claim 67
Dependent Claim
11 words
The method of claim 60 wherein the noble metal is silver.
Claim 68
Dependent Claim
11 words
The method of claim 60 wherein the noble metal is platinum.
Claim 69
Dependent Claim
11 words
The method of claim 60 wherein the noble metal is irridium.
Claim 70
Dependent Claim
11 words
The method of claim 60 wherein the noble metal is rhodium.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |