Back to results
US 4,892,862 AGranted
Process for producing superconducting material
AssigneeHitachi, Ltd.
InventorsTetsuya Ogushi, Yoshinori Hakuraku, Hisanao Ogata
Life of this patent
Estimating the term…
Abstract
Oxide materials having the formulae (L.sub.x A.sub.1-x).sub.i MO.sub.y, (L.sub.x A.sub.1-x).sub.i -M.sub.1-z Cu.sub.z O.sub.y and (L.sub.x A.sub.1-x).sub.i MO.sub.j-.delta. G.sub.k, wherein L is Sc, Y, lanthanides, etc.; A is Ba, Sr, Ca, etc.; M is V, Nb, Ta, Ti, Zr or Hf; 0<x<1; 0<z<1; i=1, 3/2 or 2; 0<y.ltoreq.4; G is F, Cl or N; .delta. is oxygen defect, and having a perovskite-like crystal structure, show superconductivity at a temperature higher than the liquid nitrogen temperature these oxide materials can be produced by a substitution diffusion reaction between a substrate and a film or layer deposited on the substrate.
Claims11
A process for producing a film of oxide superconducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i MO.sub.y ( 1) or
- (L.sub.x A.sub.1-x).sub.i M.sub.i-z Cu.sub.z O.sub.y ( 2)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- i is 1, 3/2 or 2;
- y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2;
- and z is 0<z<1, which comprises
- depositing, on a metal film of one element selected from the group consisting of the elements L, A, and M, an oxide of the rest of the elements other than that of the metal film, and
- heat treating the metal film and the resulting deposited layer to carry out a diffusion reaction therebetween.
8 more elements
A process for producing a film of oxide superconducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i MO.sub.y ( 1)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- i is 1, 3/2 or 2;
- and y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2, which comprises
- using as a target an oxide represented by the formula:
- (L.sub.x A.sub.1-x).sub.i CuO.sub.y ( 4)
- wherein L, A, x, i and y are as defined above, and as a substrate a film of the element M,
- passing an alternating electric current through the substrate so as to maintain the temperature of the substrate at 1000.degree. to 1400.degree. C.,
- conducting sputtering by using a direct current magnetron sputtering apparatus in an argon atmosphere with a pressure of 0.1 to 0.8 Torr at a sputtering voltage of 200 to 400V and a sputtering electric current of 20 mA to 100 mA, and
- conducting a diffusion reaction between the substrate and the sputtered layer.
10 more elements
A process for producing a powder of oxide superconducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i MO.sub.y ( 1)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- i is 1, 3/2 or 2;
- and y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2, which comprises
- depositing a film of pure metal of the element M on the outer surface of an oxide represented by the formula:
- (L.sub.x A.sub.1-x).sub.i CuO.sub.y ( 4)
- wherein L, A, x, i and y are as defined above, in vacuum,
- substituting the Cu of the oxide of the formula (4) with the element M at 600.degree. to 900.degree. C. by the diffusion of the element M,
- subjecting the resulting product to annealing in an oxidizing atmosphere, and
- pulverizing the resulting annealed product.
10 more elements
A process for producing a film of superconducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i MO.sub.y ( 1)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- i is 1, 3/2 or 2;
- and y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2, which comprises
- using as a substrate at least one material selected from the group consisting of silicon, aluminum oxide, silicon oxide, magnesium oxide and zirconium oxide,
- forming a metal thin film of the element M on the substrate,
- depositing a film of L.sub.x A.sub.1-x, wherein L, A and x are as defined above, on the metal thin film, and
- subjecting the resulting film to heat treatment to carry out a diffusion reaction of these elements.
8 more elements
A process for producing a superconducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i MO.sub.y ( 1)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- i is 1, 3/2 or 2;
- and y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2, which comprises
- depositing a film of L.sub.x A.sub.1-x, wherein L, A and x are as defined above, on a metal tape or a substrate of the element M, and
- subjecting the resulting film to heat treatment to carry out a diffusion reaction of these elements.
6 more elements
A process for producing a film of super-conducting material represented by the formula:
- (L.sub.x A.sub.1-x).sub.i M.sub.1-z Cu.sub.z O.sub.y ( 2)
- wherein L is at least one element selected from the group consisting of Sc, Y, lanthanide elements of atomic numbers 57 to 71, and Li, Na, K, Rb, Cs and Fr belonging to the group Ia of the periodic table;
- A is at least one element selected from alkaline earth metal elements;
- M is at least one element selected from the group consisting of V, Nb, Ta, Ti, Zr and Hf;
- x is 0<x<1;
- z is 0<z<1;
- i is 1, 3/2 or 2;
- y is 0<y.ltoreq.3 in the case of i=1, or 0<y.ltoreq.4 in the case of i=3/2 or 2, which comprises
- using a substrate made of at least one member selected from the group consisting of silicon, aluminum oxide, silicon oxide, magnesium oxide, and zirconium oxide,
- forming a metal thin film of the element M on the substrate,
- depositing an amorphous or polycrystalline film of (L.sub.x A.sub.1-x).sub.i CuO.sub.y on the metal thin film, and
- subjecting the resulting film to heat treatment to diffuse the element M into the (L.sub.x A.sub.1-x).sub.1 CuO.sub.y film.
9 more elements
A process for producing a film of La--Sr--Nb--O oxide super conducting material which comprises
- using as a target a La--Sr--cu--O.sub.4 sintered body, and as a substrate a niobium material,
- passing an alternating electric current through the substrate so as to maintain the temperature of the substrate at 1000.degree. to 1400.degree. C.,
- conducting sputtering in an argon atmosphere with a pressure of 0.1 to 0.8 Torr at a sputtering voltage of 200 to 400V and a sputtering electric current of 20 mA to 100 mA to form a film of La--Sr--Cu--O.sub.4 on the niobium substrate surface,
- conducting a diffusion reaction between the substrate and the sputtered layer, and
- subjecting the resulting niobium substrate to heat treatment at 500.degree.-600.degree. C. for 10-30 minutes in a weakly oxidizing atmosphere.
2 more elements
Dependencies are inferred from the claim text.