Lanthanum zirconate: A single buffer layer processed by solution deposition for coated conductor fabrication

A single layer of La₂Zr₂O₇ (LZO), deposited on textured Ni and Ni–1.7% Fe–3% W (Ni–W) tapes by a low-cost sol-gel process, is used as buffer layer for the growth of YBa₂Cu₃O_7−δ (YBCO) coated conductors. It is shown for the first time that such single buffer layers can be used for the deposition of YBCO yielding critical current densities (J_c) that are comparable to those typically obtained using CeO₂/YSZ/Y₂O₂ trilayers on identical substrates, i.e., in excess of 1 MA/cm² at 77 K and self-field. The properties of the YBCO films and the dependence of J_c on thickness of the LZO layer are investigated.