Deposition of (211 _∼1.0nm/123 _∼10nm)xN multilayer coated conductors on Ni-based textured substrates

Properties of multilayer (211 _∼1.0nm/123 _∼1.0nm)xN composite films deposited on buffer-coated rolling assisted biaxially textured (RABiT's™) Ni-alloy substrates were investigated providing initial results. Two different RABiT's substrates were tested: CeO ₂/YSZ/CeO ₂/Ni deposited in-situ prior to the YBCO composite deposition, and CeO ₂/YSZ/Y ₂O ₃/Ni-3%W substrates prepared in an external process. Similar transport critical current densities (J _cs) at 77K in a self-field of ∼ 0.6-1.0 MA/cm ² and transition temperatures (T _cs) ∼ 89-90 K were obtained for films deposited onto both architectures. These results were consistently achieved for the initial deposition parameters chosen on both substrates; no process optimization was conducted in this report. Compared to 123 films deposited on similar substrates, transport J _cs (77K, H _appl) were reduced slightly for H _appl ∼ < 1.5 T, but increased on average for H _appl > 1.5 T. However, this is contrary to results on single crystals which had improved current densities even at H _appl ∼ < 1.5 T; i.e. where some optimization has occurred. The surface micro structure of the multilayer films on RABiT's substrates showed flat surfaces and greatly reduced particulate formation, similar to multilayer deposition on single crystal substrates. However void formations were observed similar to deposition of 123 on RABiT's, which presumably predominately resulted from defects in the buffer layer structure.