Solution Deposition Approach to High<tex>$rm J_rm c$</tex>Coated Conductor Fabrication

Abstract

Listen

Translate article

Great strides have been made in YBCO coated conductor fabrication using the RABiTS approach in the past few years and critical current densities (J/sub c/) of over 3 MA/cm/sup 2/ on 10 meter long tapes have been achieved. Solution deposition for buffer layer processing has the potential to reduce the process complexity and make the conductor fabrication more cost-effective. In our work, we have demonstrated that several of the standard buffer layers can be replaced by sol-gel processed lanthanum zirconium oxide (LZO) layer. A J/sub c/ of about 2 MA/cm/sup 2/ has been demonstrated on LZO films for pulsed laser deposited YBCO and J/sub c/ up to 1.5 MA/cm/sup 2/ have been demonstrated for MOD-YBCO using a sputtered CeO/sub 2/ cap layer on the sol-gel LZO films. Solution processed buffer layers have been found to have rapid growth kinetics which could potentially mean high rate processing of these buffer layers. Using simulated ex-situ YBCO annealing studies, it has been determined that the performance of 80-120 nm thick LZO films is comparable to the standard 3-layer vapor deposited CeO/sub 2//YSZ/Y/sub 2/O/sub 3/ buffer stack. Using a 120 nm thick LZO layers on NiW substrates, in collaboration with American Superconductor Corp., all-solution coated conductors with the stacking sequence MOD-YBCO/Solution CeO/sub 2//Solution LZO/NiW, critical currents of up to 140 A/cm has been measured. Such high critical currents on an all-solution conductor offers promise for cost-effective scale-up of coated conductor processing.