Superconductor

Abstract

Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700° C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.

What is claimed is: .[. 
     
       1.  A superconductor comprising an A--B--Cu oxide film deposited on a metal film formed on a substrate, said A--B--Cu oxide containing elements A and B and Cu and O, the molar ratio of said elements A and B and Cu being in a range of ##EQU4## wherein the element A is one element selected from Tl, Bi, Pb, Y and lanthanum series elements (atomic number: 57-71), and the element B is one element selected from the Group IIa elements; and said metal film being a transition metal element selected from Pt, Au, Ag, Pd, Ni and Ti the composition A--B--Cu--O of said oxide film being in the form of layered perovskite-like structure..]..[.2. A superconductor according to claim 1, wherein an additional metal film is formed on said oxide film, or the oxide films and metal films are laminated alternately to form a 
     
     
        multi-layer structure..].3. A superconductor .[.according to claim 1.]. .Iadd.comprising an A--B--Cu oxide film deposited on a metal film formed on a substrate, said A--B--Cu oxide containing elements A and B and Cu and O, the molar ratio of said elements A and B and Cu being in a range of ##EQU5## wherein the element A is one element selected from Tl, Bi, Pb, Y and lanthanum series elements (atomic number: 57-71), and the element B is one element selected from the Group IIa elements; and said metal film being a transition metal element selected from Pt, Au, Ag, Pd, Ni and Ti, and the composition A--B--Cu--O of said oxide film being in the form of layered perovskite structure.Iaddend., wherein .[.the.]. .Iadd.a .Iaddend.surface of said substrate is coated with a glass film selected from the group consisting of quartz glass, high silica glass, borosilicate glass, soda-lime glass and oxynitride glass .Iadd.and wherein the glass film is positioned between the substrate and the metal film.Iaddend.. .[.4. A superconductor according to claim 1, wherein the substrate is composed of at least one single crystal material selected from MgO, sapphire (α--Al 2  O 3 ), spinel, SrTiO 3 , silicon, silicon compounds, GaAs and ferrite..]..[.5. A superconductor according to claim 1, wherein the substrate is composed of at least one chinaware material selected from alumina, MgO, ZrO 2 , steatite, forsterite, beryllium and spinel..]..[.6. A superconductor according to claim 3, using a single 
     
     
        crystal (100) plane or (110) plane MgO substrate..].7. A superconductor according to claim 3, using a single crystal R plane sapphire substrate. 
     
     
           A superconductor according to claim 3, using a single crystal C plane 
     
     
        sapphire substrate. 9. A superconductor according to claim 3, using a 
     
     
        single crystal A plane sapphire substrate. 10. A superconductor according to claim .[.2.]. .Iadd.3.Iaddend., using a single crystal (111) plane 
     
     
        spinel substrate. 11. A superconductor according to claim 3, using a 
     
     
        single crystal (110) plane spinel substrate. 12. A superconductor according to claim 3, using a single crystal (100) plane spinel substrate. .[.13. A superconductor according to claim 3, using a single crystal (100) 
     
     
        plane or (110) plane strontium titanate substrate..].14. A superconductor .[.according to claim 1.]. .Iadd.comprising an A--B--Cu oxide film deposited on a metal film formed on a substrate, said A--B--Cu oxide containing elements A and B and Cu and O, the molar ratio of said elements A and B and Cu being in a range of ##EQU6## wherein the element A is one element selected from Tl, Bi, Pb, Y and lanthanum series elements (atomic number: 57-71), and the element B is one element selected from the Group IIa elements; and said metal film being a transition metal element selected from Pt, Au, Ag, Pd, Ni and Ti, and the composition A--B--Cu--O of said oxide film being in the form of layered perovskite structure.Iaddend., using a fiber .[.substance.]. .Iadd.substrate .Iaddend.wherein the fiber is selected from the group consisting of glass fiber, carbon fiber, quartz fiber and heat resistant 
     
     
        metal alloy fibers. 15. A superconductor according to claim 14, wherein the fiber substrate is made of glass fiber, carbon fiber or a heat-resistant metal .Iadd.alloy .Iaddend.fiber .[.such as the fiber of Nb, Ti, Ta, stainless steel or the like.].. .[.16. A superconductor according to claim 1, using an amorphous solid substrate selected from the group consisting of quartz glass, purex and amorphous silicon..]..[.17. An article comprising: (a) a substrate   (b) a noble metal buffer layer selected from the group consisting of silver and gold formed on said substrate   (c) a high temperature superconductor layer consisting of Y--Ba--Cu--O formed on said buffer layer..]..[.18. An article comprising:   (a) a substrate   (b) a metal buffer layer selected from the group consisting of nickel, palladium, platinum, gold, silver and titanium formed on said substrate   (c) a high temperature superconductor layer consisting of a high temperature superconducting layer formed on said buffer   
     
     
        layer..]..Iadd.     The superconductor according to claim 15, wherein the heat-resistant metal alloy fiber is a fiber containing a metal selected from the group consisting of Nb, Ti, Ta and stainless steel..Iaddend.