US5248659A
Expired / Lapsed
US
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Process for preparing a superconducting thin oxide film
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1991-11-14
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Granted: 1993-09-28
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Expires: 2011-11-14
Abstract
Abstract In a process for preparing a thin film of a Bi-Sr-Ca-Cu-O based oxide superconductor by a laser ablation method in which a target is irradiated with a pulsed laser beam to grow a thin film on a substrate positioned to face the target, the improvement wherein the pulse rate of the pulsed laser beam is adjusted to 0.01-10 Hz and the application of the laser beam is interrupted at each time a superconducting thin oxide film is grown to a thickness equivalent to one half the unit cell or one unit cell of a Bi-Sr-Ca-Cu-O based oxide superconductor, whereby a thin film of the oxide superconductor is grown at an average growth rate of no more than 0.5 Å/sec.
Inventors
- 👤 Tatsuoki Nagaishi
- 👤 Hisao Hattori
- 👤 Hideo Itozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:44
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/24; C23C14/28; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0521; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/729; Y10S505/73; Y10S505/732
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A process for preparing a thin film of a Bi-Sr-Ca-Cu-O based oxide superconductor, comprising the steps of: positioning a substrate to face a Bi-Sr-Ca-Cu-O target in a chamber; adjusting a pulse rate of a pulsed laser beam; irradiating said target with said pulsed laser beam; interrupting application of said pulsed laser beam to the target at each time a superconducting thin oxide film is grown on said substrate to a thickness equivalent to one half the unit cell or one unit cell of a Bi-Sr-Ca-Cu-O based oxide superconductor; and repeating the irradiating step and the interrupting step, whereby said superconducting thin oxide film is grown at an average growth rate of no more than 0.5 Å/sec.
Claim 2
Dependent Claim
116 words
A process for preparing a thin film of a Bi-Sr-Ca-Cu-O based oxide superconductor, comprising the steps of: positioning a substrate to face a Bi-Sr-Ca-Cu-O target in a chamber; adjusting a pulse rate of a pulsed laser beam; irradiating said target with said pulsed laser beam; interrupting application of said pulsed laser beam to the target at each time a superconducting thin oxide film is grown on said substrate to a thickness equivalent to one half the unit cell or one unit cell of a Bi-Sr-Ca-Cu-O based oxide superconductor; and repeating the irradiating step and the interrupting step, whereby said superconducting thin oxide film is grown at an average growth rate of no more than 0.5 Å/sec.
Claim 3
Dependent Claim
25 words
A process according to claim 1, wherein said pulse rate of said pulsed laser beam is adjusted within a range of 0.01 to 10 Hz.
Claim 4
Dependent Claim
36 words
A process according to claim 1, further comprising the steps of introducing oxygen gas into said chamber up to about 400 mTorr and heating said substrate up to about 650° C. prior to the irradiating step.
Claim 5
Dependent Claim
28 words
A process according to claim 1, wherein said pulsed laser beam is an excimer laser beam having energy of 1.5 J/cm 2 and pulse rate of 1 Hz.
Claim 6
Dependent Claim
22 words
A process according to claim 1, wherein the target comprises sintered Bi 3 Sr 2 Ca 2 Cu 3 O x powder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-27 | 1997-03-29 | 1997-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-27 | 2001-03-29 | 2001-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-27 | 2005-03-29 | 2005-09-28 | $7700.00 | Window Closed / Lapsed |