Patent US5439876A successfully refreshed from Google Patents.
US5439876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making artificial layered high Tc superconductors
Assignee: International Business Machines Corp
•
Filing: 1993-08-16
•
Granted: 1995-08-08
•
Expires: 2013-08-16
Abstract
Abstract A method for making layered structures of artificial high T c superconductor compounds by which on top of a seed crystal having a lattice structure matching the lattice structure of the superconductor compound to be made, oxide layers of all constituent components are epitaxially grown in a predetermined sequence so as to create a sandwich structure not found in natural crystals. The epitaxial deposition of the constituent components is performed in a reaction chamber having evaporation facilities, inlets for metal-organic gases, and inlets for background gases including oxygen.
Inventors
- 👤 Volker Graf
- 👤 Carl A. Mueller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:40
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; B; B82; B82Y; B82Y30/00; C30B29/00; C30B29/60; C30B29/68; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0576; H10N60/0604; H10N60/80; H10N60/85; H10N60/855; H10N60/857
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
289 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, said constituent materials being deposited one at a time, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to settle on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring, prior to said exposure, the operating temperature of the current substrate surface, monitoring, prior to said exposure the operating temperature of the source of the particular constituent material and from the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber.
Claim 2
Independent Claim
289 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, said constituent materials being deposited one at a time, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to settle on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring, prior to said exposure, the operating temperature of the current substrate surface, monitoring, prior to said exposure the operating temperature of the source of the particular constituent material and from the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein the epitaxial deposition of at least part of said constituent materials is made from a gas phase.
Claim 4
Independent Claim
299 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring the operating temperature of the current substrate surface, monitoring, prior to said exposure the operating temperature of the source of the particular constituent material and from the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; p1 repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said gas phase contains the metal atoms to be deposited in the form of an organic compound of the particular metal.
Claim 5
Independent Claim
299 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring the operating temperature of the current substrate surface, monitoring, prior to said exposure the operating temperature of the source of the particular constituent material and from the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; p1 repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said gas phase contains the metal atoms to be deposited in the form of an organic compound of the particular metal.
Claim 6
Dependent Claim
27 words
The method of claim 1, characterized in that the epitaxial deposition of said constituent materials is made from at least one molecular beam of the particular material(s).
Claim 7
Independent Claim
435 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring, prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate contains of octahedral strontium titanate SrTio 3 , that in a first epitaxial operation a first monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said strontium titanate substrate, that in a second epitaxial operation a layer of octahedral cuprous oxide Cu 2 O is deposited onto said lanthanum oxide monolayer, that in a third epitaxial operation a second monolayer of lanthanum oxide La 2 O 3 is deposited onto said cuprous oxide layer, that in a fourth epitaxial operation a monolayer of octahedral titanium dioxide TiO 2 is deposited onto said second lanthanam oxide monolayer, the four individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature so as to permit the nascent la 2 CuTiO 6 crystal to be stoichiometrically correct and to assume a layered, ocathedral structure of the ABB' type.
Claim 8
Independent Claim
435 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring, prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate contains of octahedral strontium titanate SrTio 3 , that in a first epitaxial operation a first monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said strontium titanate substrate, that in a second epitaxial operation a layer of octahedral cuprous oxide Cu 2 O is deposited onto said lanthanum oxide monolayer, that in a third epitaxial operation a second monolayer of lanthanum oxide La 2 O 3 is deposited onto said cuprous oxide layer, that in a fourth epitaxial operation a monolayer of octahedral titanium dioxide TiO 2 is deposited onto said second lanthanam oxide monolayer, the four individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature so as to permit the nascent la 2 CuTiO 6 crystal to be stoichiometrically correct and to assume a layered, ocathedral structure of the ABB' type.
Claim 9
Dependent Claim
30 words
The method of claim 5, characterized in that said sequence of four epitaxial deposition operations is repeated as many times as the desired thickness of the resulting superconductor compound requires.
Claim 10
Independent Claim
446 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTiO 3 , that in a first epitaxial operation a monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said substrate, that in a second epitaxial operation a monolayer of mixed aluminum oxide Al 2 O 3+/3 and zirconium oxide Zr 4+ O 2 is deposited onto said layer of lanthanum oxide, that in a third epitaxial operation a second layer of lanthanum oxide La 2 O 3 is deposited onto said monolayer of mixed oxides, and that in a fourth epitaxial operation octahedral cuprous oxide Cu 2 O is deposited onto said second monolayer of lanthanum oxide, the four individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature so as to permit the nascent La 2 Cu(Al 1/2 ,Zr 1/2 )O 6 crystal to be stoichiometrically correct and to assume a layered, octahedral structure of the ABB' type.
Claim 11
Independent Claim
446 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTiO 3 , that in a first epitaxial operation a monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said substrate, that in a second epitaxial operation a monolayer of mixed aluminum oxide Al 2 O 3+/3 and zirconium oxide Zr 4+ O 2 is deposited onto said layer of lanthanum oxide, that in a third epitaxial operation a second layer of lanthanum oxide La 2 O 3 is deposited onto said monolayer of mixed oxides, and that in a fourth epitaxial operation octahedral cuprous oxide Cu 2 O is deposited onto said second monolayer of lanthanum oxide, the four individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature so as to permit the nascent La 2 Cu(Al 1/2 ,Zr 1/2 )O 6 crystal to be stoichiometrically correct and to assume a layered, octahedral structure of the ABB' type.
Claim 12
Independent Claim
499 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTio 3 , that in a first epitaxial operation a first monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said monocrystalline substrate, that in a second epitaxial operation a first monomolecular layer of octahedral cuprous oxide Cu 2 O is deposited on to said lanthanum oxide layer, that in a third epitaxial operation a first monomolecular layer of strontium oxide SrO is deposited onto said monolayer of cuprous oxide, that in a fourth epitaxial operation a first monomolecular layer of tungstic oxide WO 3 is deposited onto said first strontium oxide monolayer, that in a fifth epitaxial operation a second monomolecular layer of strontium oxide SrO is deposited onto said monomolecular layer of tungstic oxide, that in a sixth epitaxial operation a second monomolecular layer of octahedral cuprous oxide Cu 2 O is deposited onto said second strontium oxide layer, and that in a seventh epitaxial operation a second monomolecular layer of lanthanum oxide LaO is deposited onto said cuprous oxide layer, the seven individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperatures so as to permit the nascent Sr 2 LaCu 2 WO 9 crystal structure of the AA'B type.
Claim 13
Independent Claim
499 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTio 3 , that in a first epitaxial operation a first monomolecular layer of lanthanum oxide La 2 O 3 is deposited onto said monocrystalline substrate, that in a second epitaxial operation a first monomolecular layer of octahedral cuprous oxide Cu 2 O is deposited on to said lanthanum oxide layer, that in a third epitaxial operation a first monomolecular layer of strontium oxide SrO is deposited onto said monolayer of cuprous oxide, that in a fourth epitaxial operation a first monomolecular layer of tungstic oxide WO 3 is deposited onto said first strontium oxide monolayer, that in a fifth epitaxial operation a second monomolecular layer of strontium oxide SrO is deposited onto said monomolecular layer of tungstic oxide, that in a sixth epitaxial operation a second monomolecular layer of octahedral cuprous oxide Cu 2 O is deposited onto said second strontium oxide layer, and that in a seventh epitaxial operation a second monomolecular layer of lanthanum oxide LaO is deposited onto said cuprous oxide layer, the seven individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperatures so as to permit the nascent Sr 2 LaCu 2 WO 9 crystal structure of the AA'B type.
Claim 14
Independent Claim
508 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTiO 3 , that in a first epitaxial operation a first monomolecular layer of yttrium oxide Y 2 O 3 is deposited onto said monocrystalline substrate, that in a second epitaxial operation a first monomolecular layer of pyramidic cuprous oxide Cu 2 O is deposited onto said yttrium oxide layer, that in a third epitaxial operation a first monomolecular layer of barium oxide BaO is deposited onto said monolayer of cuprous oxide Cu 2 O, that in a fourth epitaxial operation a layer of ribbon of square planar copper oxide CuO 4 polyhedra is deposited onto said barium oxide layer, that in a fifth epitaxial operation a second monomolecular layer of barium oxide BaO is deposited onto said layer of copper oxide polyhedra, that in a sixth epitaxial operation a second monomolecular layer of pyramidic cuprous oxide Cu 2 O is deposited onto said second barium oxide layer, and that in a seventh epitaxial operation a second monomolecular layer of yttrium oxide is deposited onto said cuprous oxide layer, the seven individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature, so as to permit the nascent YBa 2 Cu 3 O 7 crystal to be stoichiometrically correct and to assume a layered, orthorhombic structure.
Claim 15
Independent Claim
508 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; and said monocrystalline substrate consists of octahedral strontium titanate SrTiO 3 , that in a first epitaxial operation a first monomolecular layer of yttrium oxide Y 2 O 3 is deposited onto said monocrystalline substrate, that in a second epitaxial operation a first monomolecular layer of pyramidic cuprous oxide Cu 2 O is deposited onto said yttrium oxide layer, that in a third epitaxial operation a first monomolecular layer of barium oxide BaO is deposited onto said monolayer of cuprous oxide Cu 2 O, that in a fourth epitaxial operation a layer of ribbon of square planar copper oxide CuO 4 polyhedra is deposited onto said barium oxide layer, that in a fifth epitaxial operation a second monomolecular layer of barium oxide BaO is deposited onto said layer of copper oxide polyhedra, that in a sixth epitaxial operation a second monomolecular layer of pyramidic cuprous oxide Cu 2 O is deposited onto said second barium oxide layer, and that in a seventh epitaxial operation a second monomolecular layer of yttrium oxide is deposited onto said cuprous oxide layer, the seven individual epitaxial operations being performed under controlled conditions regarding time of exposure, concentration of epitaxial source material, and reaction temperature, so as to permit the nascent YBa 2 Cu 3 O 7 crystal to be stoichiometrically correct and to assume a layered, orthorhombic structure.
Claim 16
Dependent Claim
21 words
The method of claim 9, characterized in that said first and second monolayers of yttrium oxide have a square planar structure.
Claim 17
Dependent Claim
42 words
The method of claim 9, characterized in that said YBa 2 Cu 3 O 7 crystal comprises at least two orthorhombic lattices consisting of Ba 2 Cu 3 O 5 with an interstacked square planar yttrium oxide Y 2 O 3 layer.
Claim 18
Dependent Claim
29 words
The method of claim 9, characterized in that said cycle of seven epitaxial deposition steps is repeated as often as the desired thickness of the resulting layered structure requires.
Claim 19
Dependent Claim
60 words
The method of claim 9, characterized in that said fourth epitaxial deposition step in which a layer of copper oxide CuO 4 is deposited, is repeated at least once prior to continuing with the fifth step of deposition to create a layered structure comprising more than one layer of copper oxide CuO 4 between consecutive layers of barium oxide BaO.
Claim 20
Independent Claim
143 words
A method for making a layered high T c superconductor by monolayer deposition, comprising the steps of: placing a substrate in a chamber, said substrate having a desired crystallographic structure allowing substantial lattice matching to said superconductor, therebeing a plurality of sources in said chamber for providing the constituents of said superconductor, heating at least one of said sources to vaporize said source and to cause the constituent in said source to be deposited on said substrate as a monoatomar or monomolecular layer thereon heating in a sequence others of said sources to vaporize said sources for deposition onto said substrate of others of said constituents as monoatomar or monomolecular layers thereon, said constituents being deposited one at a time, repeating said preceding two heating steps to deposit additional monoatomar or monomolecular layers on said substrate until the desired final superconductor is formed.
Claim 21
Independent Claim
143 words
A method for making a layered high T c superconductor by monolayer deposition, comprising the steps of: placing a substrate in a chamber, said substrate having a desired crystallographic structure allowing substantial lattice matching to said superconductor, therebeing a plurality of sources in said chamber for providing the constituents of said superconductor, heating at least one of said sources to vaporize said source and to cause the constituent in said source to be deposited on said substrate as a monoatomar or monomolecular layer thereon heating in a sequence others of said sources to vaporize said sources for deposition onto said substrate of others of said constituents as monoatomar or monomolecular layers thereon, said constituents being deposited one at a time, repeating said preceding two heating steps to deposit additional monoatomar or monomolecular layers on said substrate until the desired final superconductor is formed.
Claim 22
Dependent Claim
26 words
The method of claim 14, wherein a gas stream including oxygen is introduced into said chamber, said vaporization then forming monomolecular oxide layers on said substrate.
Claim 23
Dependent Claim
18 words
The method of claim 14, wherein said sources include the metal constituents to be present in said superconductor.
Claim 24
Dependent Claim
11 words
The method of claim 14, wherein said superconductor contains Cu-O planes.
Claim 25
Dependent Claim
17 words
The method of claim 17, where said monoatomar or monomolecular layers are epitaxially formed on said substrate.
Claim 26
Independent Claim
309 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; said superconductor contains Cu-O planes; and wherein the sequence of heating steps deposits monoatomar of monomolecular layers in a sequence other than that naturally occurring.
Claim 27
Independent Claim
309 words
A method for making artificial, layered high T c superconductor compounds by monolayer epitaxy, comprising the following steps: placing a monocrystalline substrate of a material from the group comprising strontium titanate SrTio 3 , zirconium dioxide ZrO 2 , zinc telluride Zn 1-x Se x , barium fluoride, BaF 2 , cadmium selenide Cd 1-x , and cadmium telluride Cd 1-x Te x , wherein x<1, in a chamber having a plurality of independent sources of materials for epitaxial deposition, exposing said substrate in a sequence to as many different ones of said sources of constituent materials as the superconductor compounds being made should contain, activating said sources in accordance with a pattern of activity, said pattern involving determining which particular constituent material is to be deposited at any one time; determining the amount and concentration of the particular constituent material to be emitted from said activated source determining the period of time the exposure of said substrate to the individual constituent materials should last for one monoatomar/monomolecular layer of the particular constituent material to deposit on the current substrate surface; determining the operating temperature at which the exposure is to be performed by monitoring prior to said exposure the operating temperature of the current substrate surface, monitoring prior to said exposure the operating temperature of the source of the particular constituent material and monitoring prior to said exposure the reaction temperature required for the desired high T c superconductor material to form in accordance with a particular, desired crystal structure; repeating the preceding steps as often as corresponds to the number of monomolecular/monoatomar layers the final superconductor compound should contain; cooling the resulting crystal to ambient temperature and removing it from said chamber; said superconductor contains Cu-O planes; and wherein the sequence of heating steps deposits monoatomar of monomolecular layers in a sequence other than that naturally occurring.
Claim 28
Dependent Claim
13 words
The method of claim 19, wherein said superconductor has an artificial crystallographic structure.
References Cited (Backward Citations)
US4058430A
Cited
GB2120845A
Cited
GB2162862A
Cited
US4854264A
Cited
DE3810243A1
Cited
EP0305292A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-07 | 1999-02-06 | 1999-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-07 | 2003-02-06 | 2003-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-07 | 2007-02-06 | 2007-08-08 | $7700.00 | Window Closed / Lapsed |