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US5358927A Expired / Lapsed US ⏱️ 0.0 years remaining

Growth of a,b-axis oriented pervoskite thin films

Assignee: Rutgers, The State University of New Jersey
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Filing: 1990-05-31
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Granted: 1994-10-25
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Expires: 2010-05-31
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Abstract

Abstract A method, and the resulting structure, of growing a superconducting perovskite thin film of, for example YBa2Cu3O7-x. A buffer layer of, for example, the perovskite PrBa2Cu3O7-y, is grown on a crystalline (001) substrate under conditions which favor growth of a,b-axis oriented material. Then the YBa2Cu3O7-x layer is deposited on the buffer layer under changed growth conditions that favor growth of c-axis oriented material on the substrate, for example, the substrate temperature is raised by 110 DEG C. However, the buffer layer acts as a template that forces the growth of a,b-axis YBa2Cu3O7-x, which nonetheless shows a superconducting transition temperature near that of c-axis oriented films.

Inventors

  • 👤 Arun Inam
  • 👤 Ramamoorthy Ramesh
  • 👤 Charles T. Rogers, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:50
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0912; H10N60/0941; C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/225; H10N60/0268; H10N60/0296; H10N60/0521; H10N60/0576; H10N60/0632; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/702; Y10S505/725; Y10S505/729; Y10S505/73; Y10S505/732

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 90 words
A method of growing an oriented perovskite film, comprising the steps of: depositing on a crystalline substrate a first film of a first perovskite composition under first growth conditions favoring growth of said first film as an a,b-axis oriented film; and depositing on said first film a second film of a second perovskite composition under second growth conditions favoring, in the absence of said first film, growth of said second film as a c-axis oriented film, wherein said second film grows on said first film as an a,b-axis oriented film.
Claim 2
Independent Claim 90 words
A method of growing an oriented perovskite film, comprising the steps of: depositing on a crystalline substrate a first film of a first perovskite composition under first growth conditions favoring growth of said first film as an a,b-axis oriented film; and depositing on said first film a second film of a second perovskite composition under second growth conditions favoring, in the absence of said first film, growth of said second film as a c-axis oriented film, wherein said second film grows on said first film as an a,b-axis oriented film.
Claim 3
Dependent Claim 18 words
A method as recited in claim 1, wherein said first perovskite composition differs from said second perovskite composition.
Claim 4
Dependent Claim 15 words
A method as recited in claim 2, wherein said second composition is a superconducting composition.
Claim 5
Dependent Claim 38 words
A method as recited in claim 3, wherein said first growth conditions include holding said substrate at a first temperature and said second growth conditions include holding said substrate at a second temperature different from said first temperature.
Claim 6
Dependent Claim 17 words
A method as recited in claim 4, wherein said first temperature is lower than said second temperature.
Claim 7
Dependent Claim 20 words
A method as recited in claim 3, wherein said first composition comprises PrBCO and wherein said second composition comprises YBCO.
Claim 8
Dependent Claim 38 words
A method as recited in claim 2, wherein said first growth conditions include holding said substrate at a first temperature and said second growth conditions include holding said substrate at a second temperature higher than said first temperature.
Claim 9
Dependent Claim 26 words
A method as recited in claim 7, wherein said steps of depositing said first and second films comprise pulse laser evaporation from targets onto said substrate.
Claim 10
Dependent Claim 20 words
A method as recited in claim 8, wherein said first temperature is approximately 110° C. lower than said second temperature.
Claim 11
Dependent Claim 14 words
A method as recited in claim 1, wherein said crystalline substrate comprises a perovskite.
Claim 12
Dependent Claim 15 words
A method as recited in claim 10, wherein said perovskite substrate has an (001) orientation.
Claim 13
Dependent Claim 25 words
A method as recited in claim 11, wherein said perovskite substrate has a composition chosen from the group of SrTiO 3 and LaAIO 3 .
Claim 14
Independent Claim 70 words
A method of growing an a,b-axis oriented film of a perovskite superconductor, comprising the steps of: depositing a layer of a lanthanide rare-earth barium cuprate on a surface of a crystalline material comprising an a,b-axis oriented praseodymium lanthanide rare-earth barium cuprate at deposition conditions favoring growth on a substrate of SrTiO 3 of a c-axis oriented lanthanide rare-earth barium cuprate, whereby said layer is deposited as an a,b-axis oriented layer.
Claim 15
Independent Claim 70 words
A method of growing an a,b-axis oriented film of a perovskite superconductor, comprising the steps of: depositing a layer of a lanthanide rare-earth barium cuprate on a surface of a crystalline material comprising an a,b-axis oriented praseodymium lanthanide rare-earth barium cuprate at deposition conditions favoring growth on a substrate of SrTiO 3 of a c-axis oriented lanthanide rare-earth barium cuprate, whereby said layer is deposited as an a,b-axis oriented layer.
Claim 16
Dependent Claim 20 words
A method as recited in claim 13, further comprising depositing said crystalline material on a substrate as a thin film.
Claim 17
Dependent Claim 22 words
A method as recited in claim 14, wherein said steps of depositing said layer and said crystalline material comprise pulsed laser deposition.
Claim 18
Dependent Claim 47 words
A method as recited in claim 1, wherein said a,b-axis oriented first film is oriented with one of its a-axis and b-axis perpendicular to said substrate and wherein said a,b-axis oriented second film is oriented with one of its a-axis and b-axis perpendicular to said second film.

References Cited (Backward Citations)

JPS63236794A Cited
DE3810243A1 Cited
EP0294285A1 Cited
US4943559A Cited
US4962086A Cited
JPH0244782A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-10-24 1998-04-25 1998-10-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-10-24 2002-04-25 2002-10-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-10-24 2006-04-25 2006-10-25 $7700.00 Window Closed / Lapsed

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