Effect of metal composition ratios of solutions on Jc-B properties of REBCO coated conductors fabricated by advanced TFA-MOD process

Metal organic deposition using trifluoroacetates (TFA-MOD) is expected as a low cost process of high T. superconducting coated conductors, since this method does not need any high vacuum system. The advanced TFA-MOD process enabled us to produce YBa2Cu3O7-y (YBCO) films on IBAD buffered metallic substrates (PLD-CeO2/IBAD-GZO/Hastelloy) with high critical current density (J(c)) values over 2 MA/cm(2) under the conditions of T = 77 K and the self fields. REBCO (REN and Sm) films with different compositions were fabricated on the substrates by the advanced TFA-MOD process using TFA salts of Y, Sm, Ba and Cu-Naphthenate. The films which had excess amounts of (Sm), (Sm and Cu) or (Y and Cu) in addition) at 77 K under the self fields compared to the stoichiometric 123 composition (Y:Ba:Cu = 1:23) showed higher J(c) values (>3 MA/cm(2) with that of the stoichiometric composition film. In addition, the J(c) values of the (Sm) or (Sm and Cu) added films were also improved under the high magnetic fields compared with that of the stoichiometric composition film. The origins of pinning centers were discussed from the perspectives of microstructures, crystal growth mechanisms, and so on. (C) 2007 Elsevier B.V. All rights reserved.