Development of REBCO coated conductors on textured metallic substrates

A high T-c superconducting coated conductor appears promising for AC electronic power applications such as power cables and motors due to its potential of low AC loss. We use bi-axially textured substrates for making coated conductors to take advantage of higher deposition rate and fewer numbers of buffer layers on them compared with ion beam assisted deposition (IBAD) substrates. However, the bi-axially textured substrates such as NiW tapes have magnetism, and therefore AC loss is increased. To minimize magnetism we developed a clad type substrate. The clad type substrate is made by laminating a thin bi-axially textured film on a noncrystalline base substrate. In developing the clad type substrate. we clarified that the improvement of the substrate surface flatness leads higher texture and the crystallinity of buffer layers and a superconducting layer, resulting in high critical current (I-c). We acquired the maximum I-c of 380 A/cm with the 2 mu m thick GdBaCuO superconducting film. (C) 2009 Elsevier B.V. All rights reserved.