YBCO Superconductors on Electrodeposited Biaxially Textured Buffer Layers

Raghu Bhattacharya, Sovannary Phok, Wenjun Zhao, and Andrew Norman

Abstract—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. 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 analyzed and compared to Gd₂O₃/Gd₂Zr₂O₇ . YBa₂Cu₃O_7-δ (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 was obtained for PLD YBCO deposited on ED-Gd₂O₃/Gd₂Zr₂O₇ buffer layers.

Index Terms— Biaxial texture, buffer layers, electrodeposition, pulsed laser deposition, YBCO.

Manuscript received 19 August 2008.
This work has been performed by an employee of the Midwest Research Institute under Contract No. DE-AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work.
R.N. Bhattacharya, S. Phok, W. Zhao, and A. Norman are with the National Renewable Energy Laboratory, Golden, CO 80401 USA (phone: 303-384-6477; fax: 303-384-6432; e-mail: Raghu_bhattacharya@nrel.gov).

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