Long length oxide template for YBCO coated conductor prepared by surface-oxidation epitaxy method

Abstract

A 50 m long, biaxially textured NiO buffer layer for epitaxial growth ofYBa 2Cu 3O 7− δ (YBCO) film has been fabricated on the long cube textured nickel tape using surface-oxidation epitaxy (SOE) method. The SOE-NiO layers were highly {1 0 0} 〈0 0 1〉 textured. The full width at half maximum of 10–14.5° from X-ray φ-scan ( Δφ) was in the range of 10–14.5° through the whole length. The critical current density ( J c) values exceeding 0.3 MA/cm 2 (77 K, 0 T) have been obtained in short samples of YBCO films on NiO/Ni tapes, by using thin MgO cap layer. Thirty meters long Ni-clad Ni–20wt.%Cr (Ni/NiCr) and Ni-clad austenitic stainless steel (Ni/SS) tapes were also prepared for YBCO coated conductors with higher strength and lower magnetism than those of pure nickel tape. Highly {1 0 0} 〈0 0 1〉 textured NiO layers were formed on those textured composite tapes by SOE method as same as on cube textured pure nickel tapes. YBCO films with J c of 0.1 MA/cm 2 (77 K, 0 T) have been obtained on MgO/SOE-NiO layer of short Ni/NiCr composite tape.