Title :
Characterization of Phase Evolution in YBCO Coated Conductors Produced by the Ex Situ BaF2 Process
Author :
Feenstra, R. ; List, F.A. ; Zhang, Y. ; Christen, D.K. ; Maroni, V.A. ; Miller, D.J. ; Feldmann, D.M.
Author_Institution :
Oak Ridge Nat. Lab., Oak Ridge
fDate :
6/1/2007 12:00:00 AM
Abstract :
Raman microprobe spectroscopy and scanning electron microscopy were used to study the initial nucleation and growth of YBCO in thick precursors by the BaF2 ex situ process. For quenched films of 2 mum thickness, the data indicate a low density of c-axis nuclei near the substrate, apparently due to a reduced oxygen concentration deep inside the precursor layer. Significant non c-axis growth was also observed; the majority of this material nucleates away from the substrate. Measurement of the conversion rate by in situ XRD for films in the range 0.2-2 mum suggest a weak thickness dependence.
Keywords :
Raman spectra; X-ray diffraction; barium compounds; high-temperature superconductors; liquid phase deposition; nucleation; scanning electron microscopy; superconducting thin films; yttrium compounds; Raman microprobe spectra; XRD; YBCO coated conductors; YBa2Cu3O7; nucleation; oxygen concentration; quenched films; scanning electron microscopy; size 2 mum; Annealing; Atherosclerosis; Conductors; Raman scattering; Scanning electron microscopy; Solvents; Spectroscopy; Substrates; Thick films; Yttrium barium copper oxide; High-temperature superconductors; Raman spectroscopy; superconducting epitaxial layers; thick films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2007.899994
