Title :
Development of buffer layers for high quality Tl-Pb-Sr-Ba-Ca-Cu-O thick films on flexible metal substrates
Author :
Parilla, P.A. ; McGraw, J.M. ; Schulz, D.L. ; Wendelin, J. ; Bhattacharya, R.N. ; Blaugher, R.D. ; Ginley, D.S. ; Voigt, J.A. ; Roth, E.P.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
fDate :
6/1/1997 12:00:00 AM
Abstract :
Previous work has demonstrated the ability to grow extremely high quality Tl/sub 0.5/Pb/sub 0.5/Sr/sub 1.6/Ba/sub 0.4/Ca/sub 2/Cu/sub 3/O/sub x/ epitaxial films up to 15 /spl mu/m thick using melt growth techniques on single crystal LaAlO/sub 3/ substrates. This melt growth process is an ideal candidate for producing high quality superconducting films on flexible metal substrates with textured buffer layers; however, the textured buffer layer of choice, cubic yttria stabilized zirconia (YSZ), appears to be incompatible with the melt growth of TI-Pb-Sr-Ba-Ca-Cu-O films. In this work, we investigate textured buffer layers which are compatible with the epitaxial growth of Tl/sub 0.5/Pb/sub 0.5/Sr/sub 1.6/Ba/sub 0.4/Ca/sub 2/Cu/sub 3/O/sub x/ films. Crucial properties for the successful development of a suitable buffer layer are lattice matching, chemical stability and texture. Buffer layer materials investigated are CeO/sub 2/ and LaAlO/sub 3/ grown using a UV (248 nm) pulsed excimer laser deposition system equipped with multiple targets and a controlled ambient. Influence of substrate temperature and ambient gas pressure and flow on buffer growth are analyzed via XRD characterization. Highly textured buffer layers have been fabricated.
Keywords :
X-ray diffraction; barium compounds; calcium compounds; high-temperature superconductors; lead compounds; pulsed laser deposition; strontium compounds; superconducting epitaxial layers; texture; thallium compounds; CeO/sub 2/; LaAlO/sub 3/; Tl-Pb-Sr-Ba-Ca-Cu-O; Tl-Pb-Sr-Ba-Ca-Cu-O thick films; Tl/sub 0.5/Pb/sub 0.5/Sr/sub 1.6/Ba/sub 0.4/Ca/sub 2/Cu/sub 3/O; XRD characterization; ambient gas flow; ambient gas pressure; buffer layers; chemical stability; controlled ambient; cubic yttria stabilized zirconia; epitaxial films; flexible metal substrates; lattice matching; melt growth techniques; multiple targets; pulsed excimer laser deposition system; single crystal LaAlO/sub 3/ substrates; substrate temperature; superconducting films; texture; Buffer layers; Chemicals; Epitaxial growth; Lattices; Optical materials; Pulsed laser deposition; Stability; Strontium; Substrates; Superconducting films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
