US4295147A
Expired / Lapsed
US
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Josephson devices of improved thermal cyclability and method
Assignee: International Business Machines Corp
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Filing: 1980-02-01
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Granted: 1981-10-13
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Expires: 2000-02-01
Abstract
Abstract Thin film electrodes particularly suited for Josephson devices of improved thermal cyclability are prepared by depositing thin films of superconductive metal and an intermetallic compound former on a substrate held at a temperature below about 100° K. and at a pressure below about 1×10 -7 Torr so that intermetallic compound formation occurs at the grain boundaries of the metal to inhibit grain growth. The thin film electrodes are characterized by median grain size <100 nm.
Inventors
- 👤 Charles J. Kircher
- 👤 Hung-Chang W. Huang
- 👤 Masanori Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:56
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0912; H10N60/10; H10N60/12; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/873; Y10S505/874
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
68 words
A tunnel device exhibiting Josephson tunneling current comprising: (a) a first electrode comprised of at least one superconductor, the grain size of the said superconductor being ≦100 nm; (b) a tunnel barrier in contact with said first electrode comprised of an insulating layer and being sufficiently thin that Josephson current can tunnel therethrough; and (c) a second electrode in contact with said tunnel barrier comprised of a superconductor.
Claim 2
Dependent Claim
68 words
A tunnel device exhibiting Josephson tunneling current comprising: (a) a first electrode comprised of at least one superconductor, the grain size of the said superconductor being ≦100 nm; (b) a tunnel barrier in contact with said first electrode comprised of an insulating layer and being sufficiently thin that Josephson current can tunnel therethrough; and (c) a second electrode in contact with said tunnel barrier comprised of a superconductor.
Claim 3
Dependent Claim
19 words
The tunnel device according to claim 1 wherein said tunnel barrier comprises an oxide of the first electrode superconductor.
Claim 4
Dependent Claim
26 words
The tunnel device according to claim 1 wherein said first electrode further comprises at least one intermetallic compound formed at the grain boundaries of said superconductor.
Claim 5
Dependent Claim
18 words
The tunnel device according to claim 1 wherein said first electrode superconducting material comprises lead or lead-indium alloy.
Claim 6
Dependent Claim
15 words
The tunnel device according to claim 3 wherein said intermetallic compound comprises gold and indium.
Claim 7
Dependent Claim
25 words
The tunnel device according to claim 3 wherein said first electrode superconductor comprises lead or lead-indium alloy and said intermetallic compound comprises gold and indium.
Claim 8
Dependent Claim
20 words
The tunnel device according to claim 6 wherein the second electrode superconductor comprises lead or lead-bismuth alloy or lead-gold alloy.
Claim 9
Dependent Claim
24 words
The tunnel device according to claim 1 wherein said second electrode is comprised of at least one superconductor, the grain size being ≦100 nm.
Claim 10
Dependent Claim
29 words
The tunnel device according to claim 3 wherein said intermetallic compound is present in an amount of from about 1 to about 20 weight percent of said first electrode.
Claim 11
Dependent Claim
74 words
A tunnel device exhibiting Josephson tunneling current comprising: (a) a first electrode comprised of at least one superconductor and at least one intermetallic compound, said intermetallic compound being present at the grain boundaries of said superconductor, the grain size of said superconductor being ≦100 nm; (b) a tunnel barrier on said first electrode being sufficiently thin to permit Josephson tunneling therethrough; and (c) a second electrode on said tunnel barrier comprised of a superconductor.
Claim 12
Dependent Claim
74 words
A tunnel device exhibiting Josephson tunneling current comprising: (a) a first electrode comprised of at least one superconductor and at least one intermetallic compound, said intermetallic compound being present at the grain boundaries of said superconductor, the grain size of said superconductor being ≦100 nm; (b) a tunnel barrier on said first electrode being sufficiently thin to permit Josephson tunneling therethrough; and (c) a second electrode on said tunnel barrier comprised of a superconductor.
Claim 13
Dependent Claim
15 words
The tunnel device according to claim 10 wherein said superconductor comprises lead or lead-indium alloy.
Claim 14
Dependent Claim
23 words
The tunnel device according to claim 10 wherein said superconductor comprises lead or lead-indium alloy and said intermetallic compound comprises gold and indium.
Claim 15
Dependent Claim
20 words
The tunnel device according to claim 12 wherein the second electrode superconductor comprises lead or lead-bismuth alloy or lead-gold alloy.
Claim 16
Dependent Claim
17 words
The tunnel device according to claim 13 wherein said tunnel barrier is an oxide of said superconductor.
Claim 17
Dependent Claim
55 words
An electrode for use in a tunnel device exhibiting Josephson tunneling current comprising a thin layer of at least one superconductor and at least one intermetallic compound present at the grain boundaries thereof, the grain size of said superconductor being ≦100 nm, and the surface of said layer being substantially free of said intermetallic compound.
Claim 18
Dependent Claim
55 words
An electrode for use in a tunnel device exhibiting Josephson tunneling current comprising a thin layer of at least one superconductor and at least one intermetallic compound present at the grain boundaries thereof, the grain size of said superconductor being ≦100 nm, and the surface of said layer being substantially free of said intermetallic compound.
Claim 19
Dependent Claim
24 words
The electrode according to claim 15 further comprising a tunnel barrier on said layer and being sufficiently thin that Josephson current can tunnel therethrough.
Claim 20
Dependent Claim
16 words
The electrode according to claim 16 wherein said tunnel barrier comprises an oxide of said superconductor.
Claim 21
Dependent Claim
14 words
The electrode according to claim 15 wherein said superconductor comprises lead or lead-indium alloy.
Claim 22
Dependent Claim
14 words
The electrode according to claim 15 wherein said intermetallic compound comprises gold and indium.
Claim 23
Dependent Claim
22 words
The electrode according to claim 15 wherein said superconductor comprises lead or lead-indium alloy and said intermetallic compound comprises gold and indium.
Claim 24
Dependent Claim
53 words
An electrode for use in a tunnel device exhibiting Josephson tunneling current comprising a thin layer of lead or lead-indium alloy having a grain size ≦100 nm and an intermetallic compound of gold and indium present at the grain boundaries thereof, the surface of said layer being substantially free of said intermetallic compound.
Claim 25
Dependent Claim
53 words
An electrode for use in a tunnel device exhibiting Josephson tunneling current comprising a thin layer of lead or lead-indium alloy having a grain size ≦100 nm and an intermetallic compound of gold and indium present at the grain boundaries thereof, the surface of said layer being substantially free of said intermetallic compound.
Claim 26
Dependent Claim
24 words
Th electrode according to claim 21 further comprising a tunnel barrier on said layer and being sufficiently thin that Josephson current can tunnel therethrough.
Claim 27
Dependent Claim
16 words
The electrode according to claim 22 wherein said tunnel barrier comprises an oxide of said electrode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |