Growth Conditions of Sequentially Electrodeposited Buffer Layers for YBCO Superconductor

We report recent technical advances in the fabrication by sequential electrodeposition (ED) of Gd₂O₃/Gd₂Zr₂O₇ buffer architecture. A systematic study is performed for a fundamental understanding of the buffer structure grown by ED. The electrolyte composition, solution flow rate, composition/concentration of chemicals, and annealing conditions are found to affect considerably the deposition of the layer, formation of the pyrochlore oxide, and film texture. The as-deposited and annealed films were analyzed by inductively coupled plasma (ICP), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Smooth and crack-free layers were obtained. The surface roughness of the bilayer buffer was about 3 nm. Both layers were biaxially textured. The out-of-plane mosaic spread Deltaomega was about 6deg and 7.8deg for Gd₂Zr₂O₇ and Gd₂O₃ grains, respectively. The in-plane grain dispersion Deltaphi was 8.4deg and 9.3deg for Gd₂Zr₂O₇ and Gd₂O₃ layers, respectively.