A single oxide buffer layer on a cube-textured Ni substrate for the development of YBCOcoated conductors by photo-assisted MOCVD

Abstract

Large-scale commercial applications of high-temperature superconducting (HTS)YBa2Cu3O7−x (YBCO)-based second generation coated conductors require simple and cost-effectiveprocess technologies to fabricate the buffer layer(s) and YBCO superconducting layer.Sm0.2Ce0.8O2+x (SCO) thick films have been epitaxially deposited on roll-textured Ni substrates as the singlebuffer layer for HTS coated conductors by using high-rate photo-assisted metal–organicchemical vapour deposition (PhAMOCVD) at a relatively low deposition temperature of600 °C. YBCO superconducting films were then successfully deposited on these thick SCO singlebuffer layers by the same high-rate PhAMOCVD process, and yielded critical current densities(Jc)of ∼0.52 MA cm−2 at 77 K and zero applied field. X-ray diffraction and scanning electron microscopeanalyses of SCO/Ni samples revealed very good crystalline structure and surfacemorphology for the SCO single buffer layers. These results suggest that SCOsingle buffer layer, as well as the YBCO conductors, fabricated by the high-ratePhAMOCVD technique may offer great potential for manufacturing YBCO coatedconductors.