Methods for forming superconducting conductors

Abstract

A method for producing a superconducting conductor is disclosed, including providing a substrate, depositing a buffer film having a biaxial texture to overlie the substrate by reactive sputtering, and depositing a superconducting layer to overlie the buffer film. Deposition of the buffer film is carried out by exposing the substrate along a deposition zone to a material plume generated by bombarding a target in the presence of a magnetic field, the deposition zone having a length of at least 1.0 m. The assist ions may be generated from a gridless ion source. The buffer film may have a biaxial texture having an out-of-plane crystallographic texture represented by a mosaic spread of not greater than 30°.

1 . A method for producing a superconducting conductor, comprising:
 providing metal alloy substrate in a deposition chamber;   forming a material plume in the deposition chamber, the material plume comprising metallic elements from at least one metallic target;   reacting the metallic elements to form a depositing species that deposits to form a buffer film overlying the substrate;   exposing the substrate to assist ions during deposition of the depositing species to form the buffer film, the buffer film having a biaxial texture and having an in-plane mosaic spread ΔΦ not greater than 30°; and   depositing a superconductor layer to overlie the buffer film.   
   
   
       2 . The method of  claim 1 , wherein reacting includes oxidizing the metallic elements to form a metal oxide depositing species. 
   
   
       3 . The method of  claim 2 , wherein the metallic elements are selected from the group consisting of Mg, Ni, Ce, Y, Ti, Sn, Mn, Fe, Cu and rare earth elements. 
   
   
       4 . The method of  claim 3 , wherein the buffer film is selected from the group consisting of MgO, NiO, YSZ, CeO 2 , Y 2 O 3 , TiO 2 , SnO 2 , Mn 3 O 4 , Fe 3 O 4 , Cu 2 O, and RE 2 O 3 , wherein RE is a rare earth element. 
   
   
       5 . The method of  claim 1 , wherein the forming the material plume and reacting the metallic elements are carried out by reactive sputtering. 
   
   
       6 . The method of  claim 1 , wherein reactive sputtering is reactive magnetron sputtering such that the buffer film is deposited by ion beam assisted deposition incorporating reactive magnetron sputtering. 
   
   
       7 . A method for producing a superconducting conductor, comprising:
 providing metal alloy substrate in a deposition chamber;   forming a material plume in the deposition chamber, the material plume comprising metallic elements from at least one metallic target;   reacting the metallic elements to form a depositing species that deposits to form a buffer film overlying the substrate;   exposing the substrate to assist ions from a gridless ion source during deposition of the depositing species to form the buffer film, the buffer film having a biaxial texture and having an in-plane mosaic spread ΔΦ not greater than 30°; and   depositing a superconductor layer to overlie the buffer film.   
   
   
       8 . The method of  claim 1 , wherein the buffer film has an out-of-plane crystallographic texture having a mosaic spread of not greater than 30°, wherein the mosaic spread is represented by a full-width-at-half-maximum value of an x-ray diffraction peak obtained by a (001) polefigure measurement. 
   
   
       9 . The method of  claim 8 , wherein the buffer film has an out-of-plane crystallographic texture having a mosaic spread of not greater than 15°. 
   
   
       10 . The method of  claim 1 , wherein the buffer film has a rock-salt-like crystal structure. 
   
   
       11 . The method of  claim 1 , wherein the material plume is generated by bombarding the at least one target. 
   
   
       12 . (canceled) 
   
   
       13 . The method of  claim 1 , wherein the metal alloy comprises a Ni-based alloy. 
   
   
       14 . The method of  claim 1 , wherein the superconductor layer comprises a high temperature superconductor material, having a critical temperature T c  not less than about 77 K. 
   
   
       15 . The method of  claim 14 , wherein the superconductor material comprises YBCO. 
   
   
       16 . The method of  claim 1 , wherein the target has a length not less than about 1.0 m. 
   
   
       17 . The method of  claim 1 , wherein the in-plane mosaic spread ΔΦ is not greater than 20°. 
   
   
       18 . The method of  claim 1 , wherein the in-plane mosaic spread ΔΦ is not greater than 15°.