EP0305292A2
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A process for preparing a thin film of superconducting compound oxide
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1988-08-24
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Granted: —
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Expires: 2008-08-24
Abstract
Abstract A process for preparing a superconducting thin film of a compound oxide by a process which is similar to MBE technique. In the present process, a plurality of atom beams or molecular beams each contains one element selected from constituent elements of the compound oxide are directed onto a substrate in a predetermined order, so that a plurality of mono-molecular layers are deposited on the substrate.
Inventors
- 👤 Keizo Itami Works Harada
- 👤 Naoji Itami Works Fujimori
- 👤 Shuji Itami Works Yazu
- 👤 Tetsuji Itami Works Jodai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 20:10
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/08; C23C14/087; C23C14/22; C23C14/24; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/225; C30B29/60; C30B29/68; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0381
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
70 words
A process for preparing a superconducting thin film of a compound oxide, characterised in that a plurality of atom beams or molecular beams each contains one element selected from constituent elements of the compound oxide are directed onto a substrate in a predetermined order by the molecular beam epitaxy (MBE) technique so that a plurality of monomolecular layers of oxides of the selected element are deposited on the substrate successively.
Claim 2
Dependent Claim
70 words
A process for preparing a superconducting thin film of a compound oxide, characterised in that a plurality of atom beams or molecular beams each contains one element selected from constituent elements of the compound oxide are directed onto a substrate in a predetermined order by the molecular beam epitaxy (MBE) technique so that a plurality of monomolecular layers of oxides of the selected element are deposited on the substrate successively.
Claim 3
Dependent Claim
28 words
A process set forth in Claim 1, characterized in that each of said molecular beams contains one element selected from constituent elements of the compound oxide and oxygen.
Claim 4
Dependent Claim
24 words
A process set forth in Claim 2, characterized in that each of said molecular beams is produced from an oxide of the selected element.
Claim 5
Dependent Claim
42 words
A process set forth in Claim 1, characterized in that each of said atom beams containing one element selected from constituent elements of the compound oxide is directed towards the substrate while oxygen is supplied by means of an oxygen ion gun.
Claim 6
Dependent Claim
49 words
A process set forth in Claim 1, characterized in that each of said atom beams containing one element selected from constituent elements of the compound oxide is directed towards the substrate to deposit one layer of the selected element and then oxygen alone is directed onto the deposited layer.
Claim 7
Dependent Claim
71 words
A process set forth in Claim 5, characterized in that each of said atom beams containing one element selected from constituent elements of the compound oxide is directed towards the substrate to deposit one layer of the selected element and then a molecular beam consists of an oxygen containing a compound which can easily release free oxygen when the molecular beam arrives at the substrate is directed to the deposited layer.
Claim 8
Dependent Claim
60 words
A process set forth in Claim 5, characterized in that each of said atom beams containing one element selected from constituent elements of the compound oxide is directed towards the substrate to deposit one layer of the selected element and then oxygen atom or molecular is flashed onto the deposited layer locally in the MBE unit without breakage of vacuum.
Claim 9
Dependent Claim
95 words
A process set forth in Claim 5, characterized in that each of said atom beams containing one element selected from constituent elements of the compound oxide is directed towards the substrate to deposit one layer of the selected element, then, an organic compound containing oxygen atom therein is directed to the deposited layer so that the organic compound is bonded to the deposited layer, and then a chemical bond between an oxygen and a residual group of the organic compound is cut by an excimer laser to leave oxygen atom alone on the deposited element.
Claim 10
Dependent Claim
39 words
A process set forth in any on of Claim 1 to 8, characterized in that said substrate is heated at a temperature between 200 and 1,000 °C during the monoatom layers or monomolecular layers are deposited on the substrate.
Claim 11
Dependent Claim
30 words
A process set forth in any one of Claim 1 to 9, characterized in that the thin film obtained is further heat-treated at a temperature between 200 and 1,000 °C.
Claim 12
Dependent Claim
145 words
A process set forth in any one of Claim 1 to 10, characterized in that said compound oxide is represented by the general formula: (α 1-x β x )γ y O z in which α stands for an element selected from IIIa group of the Periodic Table, β stands for an element selected from IIa group of the Periodic Table, and γ stands for an element selected from a group comprising Ib, IIb, IIIb, IVa and VIIIa groups of the Periodic Table, x is an atomic ratio of β with respect to (α+β) and has a range of 0.1 ≦ x ≦ 0.9, and y and z are respective atomic ratios with respect to (α 1-x β x ) which is considered to be equal to 1 and each satisfies a respective range of 0.4 ≦ y ≦ 3.0 and 1 ≦ z ≦ 5.
Claim 13
Dependent Claim
132 words
A process set forth in Claim 11, characterized in that the following mono-molecular layers are deposited on the substrate in the following order: 1st layer : a mono-molecular layer composed of said element γ and oxygen, 2nd layer : a mono-molecular layer composed of said element β and oxygen, 3rd layer : a mono-molecular layer composed of said element γ and oxygen, 4th layer : a mono-molecular layer composed of said element α and oxygen, 5th layer : a mono-molecular layer composed of said element γ and oxygen, 6th layer : a mono-molecular layer composed of said element β and oxygen, 7th layer : the same mono-molecular layer as the 1st layer, and then the same order as above from the 2nd layer to the 6th layer is repeated for several times.
Claim 14
Dependent Claim
52 words
A process set forth in Claim 11 or 12, characterized in that said element α is at least one element selected from a group comprising Y, La, Gd, Dy, Ho, Er, Tm, Yb, Nd, Sm, Eu and Lu and said element β is Ba or Sr and said element γ is Cu.
Claim 15
Dependent Claim
31 words
A process set forth in any one of Claim 11 to 13, characterized in that the thin film of the compound oxide has a perovskite type or quasi-perovskite type crystal structure.
Claim 16
Dependent Claim
27 words
A process set forth in any one of Claim 1 to 14, characterized in that said substrate is made of a single crystal of MgO or SrTiO₃.
Claim 17
Dependent Claim
31 words
A process set forth in Claim 15, characterized in that said superconducting thin film is deposited on a {001} plane or {110} plane of a single crystal of MgO or SrTiO₃.
Claim 18
Dependent Claim
117 words
A process set forth in any one of Claim 1 to 10, characterised in that thin film is composed essentially of a compound oxide represented by the formula: Θ₄(Φ 1-q , Ca q ) m Cu n O p+r in which Θ stands for Bi or Ti, Φ stands for Sr when Θ is Bi and stands for Ba when Θ is Tl, m and n are numbers each satisfying ranges of 6 ≦ m ≦ 10 and 4 ≦ n ≦ 8 respectively, p = (6+m+n), q is a number which satisfies a range of 0 < q < 1, and r is a number which satisfies a range of -2 ≦ r ≦ + 2.
Claim 19
Dependent Claim
152 words
A process set forth in Claim 17, characterized in that the following monomolecular layers are deposited on the substrate in the following order: 1st layer : a monomolecular layer composed of Tl (or Bi) and oxygen, 2nd layer : a monomolecular layer composed of Ba (or Sr) and oxygen, 3rd layer : a monomolecular layer composed of Cu and oxygen, 4th layer : a monomolecular layer composed of Ca and oxygen, 5th layer : a monomolecular layer composed of Cu and oxygen, 6th layer : a monomolecular layer composed of Ca and oxygen, 7th layer : a monomolecular layer composed of Cu and oxygen, 8th layer : a monomolecular layer composed of Ba (or Sr) and oxygen, 9th layer : a monomolecular layer composed of Tl (or Bi) and oxygen, 10th layer : a monomolecular layer composed of Tl (or Bi) and oxygen, and then the same order as above is repeated.
References Cited (Backward Citations)
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