Microstructural Development in YBA₂CU₃O₇ Coated Conductors Based on Ex Situ YBCO Conversion Processes

Conference · Sat Jan 01 00:00:00 EST 2005

OSTI ID:1003282

Holesinger, T. G. ^[1]; Arendt, P. N. ^[1]; Groves, J. R. ^[1]; Stan, L. ^[1]; Kennison, J. A. ^[1]; DePaula, R. F. ^[1]; Feenstra, Roeland ^[2]; Gapud, Albert Agcaoili ^[2]; Specht, Eliot D ^[2]; Feldmann, D. M. ^[3]; Kim, S. I. ^[3]; Larbalestier, D. C. ^[3]; Zhang, W. ^[4]; Kodenkandath, Thomas ^[4]; Li, Xiaoping ^[4]; Thompson, E. ^[4]; Verebelyi, D. T. ^[4]; Thieme, C. L. H. ^[4]

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1. Los Alamos National Laboratory (LANL)
2. ORNL
3. University of Wisconsin, Madison
4. American Superconductor Corporation, Westborough, MA

Ex-situ conversion of YBA{sub 2}CU{sub 3}O{sub 7} precursors is an economically attractive process for adding the superconducting layer to a coated conductor substrate. Understanding the phase conversion process and final microstructural assemblage is crucial to maximizing the superconducting properties. Each process used to build a YBA{sub 2}CU{sub 3}O{sub 7} (Y-123) coated conductor creates an interface along which defects or interfacial reactions may result. These defects can be additive and propagate through the entire film structure to affect the growth and properties of the superconducting film. The effects of substrate features, buffer layers, and conversion processes of the ex-situ Y-123 films on the resulting microstructures are discussed. Interfacial reactions between the substrate, buffer layers, and Y-123 films are examined. Y-123 films produced from BaF{sub 2}-based precursors deposited by e-beam evaporation or metal organic deposition (MOD) of trifluroacetates are compared in terms of their final microstructures, phase assemblage, and superconducting properties. The initial stages of processing during which phase segregation can occur, Y-123 and secondary phase development, and the degree of conversion completion in fully processed coated conductors are also examined. Implications for thick film (t > 1 {micro}m) development and structural refinements are discussed.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1003282
• Resource Relation: Conference: 204th Electrochemical Society's Fall Meeting, Orlando, FL, USA, 20031012, 20031017
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADDITIVES
BUFFERS
DEFECTS
DEPOSITION
EVAPORATION
PROCESSING
SEGREGATION
SUBSTRATES
SUPERCONDUCTING FILMS