Long-length Y-Ba-Cu-O coated conductors produced by surface-oxidation epitaxy method

A 50-m long, biaxially textured NiO buffer layer for epitaxial growth of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//(YBCO) film has been fabricated on a long length cube-textured Ni tape using the surface-oxidation epitaxy (SOE) technique. The thickness of NiO layer was arranged to be around 3 /spl mu/m. The tape manufacturing speed was 15 m/h, The SOE-NiO layer was highly [100] oriented and the full width at half maximum from the X-ray /spl phi/-scan for NiO(111) was varied from 13 to 19 degrees in the whole length. J/sub c/ values exceeding 0.3 MA/cm/sup 2/ at 77 K and self field have been obtained in short samples of YBCO films on NiO/Ni tapes, by using a thin MgO cap layer with the thickness of about 100 nm. Crystal orientation control of YBCO coated conductors by the SOE method is very effective even for the long length Ni tapes.