All Japan efforts on R&D of HTS coated conductors for future applications

Abstract

Abstract The current status of R&D on coated conductors in Japan, which includes developments of textured metal substrates including surface-oxidation epitaxy, ion beam assisted deposition (IBAD) and inclined substrate deposition (ISD) for a buffer layer, and pulsed laser deposition (PLD) and metal organic deposition (MOD) for the superconducting layer was reviewed. In the development of textured substrate group, textured long tapes with high strength were realized by a clad-type composite in both Ag- and Ni-systems. On the other hand, the textured buffer layer group also achieved long tapes over several tens meters with highly textured buffer layer by ISD and IBAD methods. Furthermore, we have developed a coated conductor tape of 46 m in length by means of IBAD for textured buffer and PLD for YBCO layer, with high Ic of 74 A at 77 K. Additionally, it was found that thick CeO2 cap layer on IBAD buffer layer can make the in-plane alignment improve in shorter time. This technique can realize higher production rate using IBAD method. Furthermore, trifluoroacetates (TFA-MOD) process has also developed as a low-cost processing. In this approach, the high critical current of 210 A was obtained in thick film fabricated by the multi-coating TFA-MOD method.