Electrodeposited Biaxially Textured Buffer Layers for YBCO Superconductors

Non-vacuum electrodeposition (ED) was used to prepare simplified Gd₂O₃/Gd₂Zr₂O₇ and CeO₂/Gd₂Zr₂O₇ buffer layers on a Ni-W substrate. Post-annealing conditions of electrodeposited precursor films were optimized to obtain high-quality biaxially textured buffer layers. The buffer layers were characterized by X-ray diffraction, optical profiling, and transmission electron microscopy (TEM). The effect of the cap layer thickness on the surface morphology and texture of the buffers was also studied. The microstructure of CeO₂/Gd₂Zr₂O₇ was analysed and compared to Gd₂O₃/Gd₂Zr₂O₇. The high-resolution TEM shows biaxially textured crystalline elctrodeposited Gd₂O₃ and CeO₂ cap layers on the electrodeposited Gd₂Zr₂O₇ layers without any defects. YBa₂Cu₃O_7-delta (YBCO) superconductor was deposited by pulsed laser deposition (PLD) on the simplified ED-Gd₂O₃/Gd₂Zr₂O₇ and ED-CeO₂/Gd₂Zr₂O₇ buffers. Transport current density of 3.3 MA/cm² at 77 K was obtained for PLD YBCO deposited on ED-Gd₂O₃/Gd₂Zr₂O₇ buffer layers.