Electrodeposited Biaxially Textured Buffer Layers for YBCO Superconductors

Non-vacuum electrodeposition (ED) was used to prepare simplified Gd2O3/Gd2Zr2O7and CeO2/Gd2Zr2O7buffer 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/Gd2Zr2O7was analysed and compared to Gd2O3/Gd2Zr2O7. The high-resolution TEM shows biaxially textured crystalline elctrodeposited Gd2O3and CeO2cap layers on the electrodeposited Gd2Zr2O7layers without any defects. YBa2Cu3O7-delta(YBCO) superconductor was deposited by pulsed laser deposition (PLD) on the simplified ED-Gd2O3/Gd2Zr2O7and ED-CeO2/Gd2Zr2O7buffers. Transport current density of 3.3 MA/cm2at 77 K was obtained for PLD YBCO deposited on ED-Gd2O3/Gd2Zr2O7buffer layers.