Chemical solution deposition of lanthanum zirconate buffer layers on biaxially textured Ni-1.7% Fe-3% W alloy substrates for coated-conductor fabrication

Sol-gel processing of La₂Zr₂O₇ (LZO) buffer layers on biaxially textured Ni-1.7% Fe-3% W alloy substrates using a continuous reel-to-reel dip-coating unit has been studied. The epitaxial LZO films obtained have a strong cube texture and uniform microstructure. The effects of increasing the annealing speed on the texture, microstructure, and carbon content retained in the film were studied. On top of the LZO films, epitaxial layers of yttria-stabilized zirconia and Ceria (CeO₂) were deposited using rf sputtering, and YBa₂CU₃O_x (YBCO) film were then deposited using pulsed laser deposition. Critical current densities (J_c) of 1.9 MA/cm² at 77 K and self-field and 0.34 MA/cm² at 77 K and 0.5 T have been obtained on these films. These values are comparable to those obtained on YBCO films deposited on all-vacuum deposited buffer layers and the highest ever obtained using solution seed layers.