Another approach for controlling size and distribution of nanoparticles in coated conductors fabricated by the TFA-MOD method

A new process, which is conceptually different from that reported so far, was developed for positive and direct control of the size and distribution of BaZrO 3 (BZO) nanoparticles acting as the effective magnetic flux pinning centers for coated conductors (CCs) fabricated on buffered metal substrates by the trifluoroacetate-based metal-organic decomposition method. The (Y,Gd)Ba 2 Cu 3 O 6+ δ (YGdBCO) phase crystallization heat-treatment process was applied one time to a multi-layered precursor prepared by repeating the coating/calcination process of the extremely thin layer of a few tens of nanometers. The size of BZO nanoparticles refined with thinning the once coated film thickness ( d once ) even in the same total film thickness of 0.6−0.7 μ m, consequently the critical current density in magnetic-field ( J c ( B )) was increased. A YGdBCO CC fabricated with d once of 30 nm revealed very high J c ( B ∣∣ c ) characteristics of 0.26 and 1.60 MA cm −2 at 77 and 65 K, respectively, for 3.0 T.