EP0329603A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Grain boundary junction devices using high-TC superconductors
Assignee: International Business Machines Corp
•
Filing: 1989-01-19
•
Granted: —
•
Expires: 2009-01-19
Abstract
Abstract High-T c superconducting devices are described in which controlled grain boundaries (GB) in a layer (12) of the superconductors form a weak link or barrier between superconducting grains (A, B) of the layer (12). A method is described for reproducibly fabricating these devices, including first preparing a substrate (10) to include at least one grain boundary (GB) therein. A high-T c superconductor layer (12) is then epitaxially deposited on the substrate (10) in order to produce a corresponding grain boundary (GB) in the superconducting layer (12). This superconducting layer (12) is then patterned to leave at least two regions on either side of the grain boundary (GB), the two regions functioning as contact areas for a barrier device including the grain boundary (GB) as a current flow barrier. Electrical contacts (16) can be made to the superconducting regions (A, B) so that bias currents can be produced across the grain boundary (GB) which acts as a tunnel barrier or weak link connection.
Inventors
- 👤 Praveen Chaudhari
- 👤 Cheng-Chung John Chi
- 👤 Duane Brian Dimos
- 👤 Jochen Dieter Mannhardt
- 👤 Chang Chyi Tsuei
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 04:37
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0912; H10N60/0941; H10N60/10; H10N60/12; H10N60/124; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/702; Y10S505/725; Y10S505/728
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
Grain boundary junction devices, characterized by a first superconducting electrode comprised of a first grain (A) of a high-T c superconductor, a second superconducting electrode comprised of a second grain (B) of a high Tc superconductor, a grain boundary (GB) located between said first and second superconducting grains (A, B), and providing a potential barrier to the flow of electrons thereacross, said first and second grains (A, B) being in a single epitaxial layer (12, 24) of high-T c superconducting material, said grain boundary (GB) having a plane substantially transverse to the plane of said epitaxial layer (12, 24) of high-T c superconducting material, and a crystalline substrate (10, 22, 32) on which said single epitaxial layer (12, 24) of high-T c superconducting material is epitaxially deposited, ially deposited, said substrate (10, 22, 32) having a grain boundary (GB) therein which is mapped into said epitaxial superconducting layer (12, 24).
Claim 2
Dependent Claim
150 words
Grain boundary junction devices, characterized by a first superconducting electrode comprised of a first grain (A) of a high-T c superconductor, a second superconducting electrode comprised of a second grain (B) of a high Tc superconductor, a grain boundary (GB) located between said first and second superconducting grains (A, B), and providing a potential barrier to the flow of electrons thereacross, said first and second grains (A, B) being in a single epitaxial layer (12, 24) of high-T c superconducting material, said grain boundary (GB) having a plane substantially transverse to the plane of said epitaxial layer (12, 24) of high-T c superconducting material, and a crystalline substrate (10, 22, 32) on which said single epitaxial layer (12, 24) of high-T c superconducting material is epitaxially deposited, ially deposited, said substrate (10, 22, 32) having a grain boundary (GB) therein which is mapped into said epitaxial superconducting layer (12, 24).
Claim 3
Dependent Claim
26 words
Devices in accordance with claim 1, characterized in that the structure comprising said first and second electrodes separated by said grain boundary (GB) is substantially planar.
Claim 4
Dependent Claim
32 words
Devices in accordance with claim 1, characterized in that the high-T c superconducting material of said layer (12, 24) is a copper oxide material having a superconducting onset temperature greater than 77K.
Claim 5
Dependent Claim
21 words
Devices in accordance with claim 3, characterized in that the said superconducting material includes a rare earth or rare earth-like element.
Claim 6
Dependent Claim
18 words
Devices in accordance with claim 3, characterized in that the said superconducting material includes an alkaline earth element.
Claim 7
Dependent Claim
83 words
Devices in accordance with claim 1, characterized in that said layer (12, 24) of superconducting material includes a plurality of superconducting regions, and that pairs of said regions are located on opposite sides of said grain boundary (GB) in said layer (12, 24), and that electrical means (16, 18) are connected to said pairs of said superconducting regions in said layer (12, 24) for producing electron flow across said grain boundary (GB) in locations therealong defined by each said pair of superconducting regions.
Claim 8
Dependent Claim
48 words
Devices in accordance with claim 6, characterized in that said grain boundary has a width of about the order of the unit cell size of said superconducting material, and that said grain boundary forms a weak coupling path between the superconducting regions in each pair of such regions.
Claim 9
Dependent Claim
24 words
Devices in accordance with claim 6, characterized in that at least two of said pairs of superconducting regions are electrically separate from one another.
Claim 10
Dependent Claim
37 words
Devices in accordance with claim 6, characterized in that at least two of said pairs of superconducting regions are electrically connected in a superconducting loop broken by said grain boundary (GB), thereby forming a SQUID (Fig. 10).
Claim 11
Dependent Claim
99 words
Method for making grain boundary junction devices of high-T c copper oxide superconducting material, comprising the steps of: providing a crystalline substrate (10, 22, 32) having a grain boundary (GB) therein, forming a layer (12, 24) of high-T c superconducting material with a grain boundary therein having a predetermined location and orientation in said superconducting material, patterning said superconducting material to electrically isolate two regions therein located on opposite sides of said grain boundary (GB), and providing electrical connections (16) to said superconducting regions to permit the producing of current flow between said regions through said grain boundary (GB).
Claim 12
Dependent Claim
99 words
Method for making grain boundary junction devices of high-T c copper oxide superconducting material, comprising the steps of: providing a crystalline substrate (10, 22, 32) having a grain boundary (GB) therein, forming a layer (12, 24) of high-T c superconducting material with a grain boundary therein having a predetermined location and orientation in said superconducting material, patterning said superconducting material to electrically isolate two regions therein located on opposite sides of said grain boundary (GB), and providing electrical connections (16) to said superconducting regions to permit the producing of current flow between said regions through said grain boundary (GB).
Claim 13
Dependent Claim
33 words
Method in accordance with claim 10, characterized in that at least two high-T c superconducting regions are connected to form a loop of high-T c superconducting material having said grain boundary (GB) therein.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.