Grain Orientations and Grain Boundary Networks of YBa2Cu3O7-δ Films Deposited by Metalorganic and Pulsed Laser Deposition on Biaxially Textured Ni-W Substrates
- University of Wisconsin, Madison
- Los Alamos National Laboratory (LANL)
- ORNL
- American Superconductor Corporation, Westborough, MA
We report a detailed study of the grain orientations and grain boundary (GB) networks in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) films {approx}0.8 m thick grown by both the in situ pulsed laser deposition (PLD) process and the ex situ metalorganic deposition (MOD) process on rolling-assisted biaxially textured substrates (RABiTS). The PLD and MOD growth processes result in columnar and laminar YBCO grain structures, respectively. In the MOD-processed sample [full-width critical current density J{sub c}(0 T, 77 K) = 3.4 MA/cm{sup 2}], electron back-scatter diffraction (EBSD) revealed an improvement in both the in-plane and out-of-plane alignment of the YBCO relative to the template that resulted in a significant reduction of the total grain boundary misorientation angles. A YBCO grain structure observed above individual template grains was strongly correlated to larger out-of-plane tilts of the template grains. YBCO GBs meandered extensively about their corresponding template GBs and through the thickness of the film. In contrast, the PLD-processed film [full width J{sub c}(0 T, 77 K) = 0.9 MA/cm{sup 2}] exhibited nearly perfect epitaxy, replicating the template grain orientations. No GB meandering was observed in the PLD-processed film with EBSD. Direct transport measurement of the intra-grain J{sub c}(0 T, 77 K) values of PLD and MOD-processed films on RABiTS revealed values up to 4.5 and 5.1 MA/cm{sup 2}, respectively. As the intra-grain J{sub c} values were similar, the significantly higher full-width J{sub c} for the MOD-processed sample is believed to be due to the improved grain alignment and extensive GB meandering.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- OE USDOE - Office of Electric Transmission and Distribution
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 978174
- Journal Information:
- Journal of Materials Research, Vol. 21, Issue 4; ISSN 0884-2914
- Country of Publication:
- United States
- Language:
- English
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