Nano-engineered defect structures in Ce- and Ho-doped metal-organic chemical vapor deposited YBa{sub 2}Cu{sub 3}O{sub 3+{delta} }films : correlation of structure and chemistry with flux pinning performance.

Journal Article · Wed Jun 01 04:00:00 EDT 2011 · J. Appl. Phys.

DOI:https://doi.org/10.1063/1.3592244· OSTI ID:1020704

Aytug, T; Chen, Z; Maroni, V A; Miller, D J; Cantoni, C; Specht, E D; Kropf, A J; Zaluzec, N; Zhang, Y; Zuev, Y; Paranthaman, M ^[1]

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1. Materials Science Division

This study reports on the fabrication of metal-organic chemical vapor deposited (MOCVD) YBa{sub 2}Cu{sub 3}O{sub 6+{delta}} (YBCO) films doped with varying amounts of Ce and Ho and the characterization of their electrical, microstructural, and chemical properties. The films are prepared by vapor phase deposition of a Y-Ba-Cu precursor mix containing controlled amounts of Ce and Ho onto buffered metal strip templates. The comprehensive characterization of these films by critical current measurement, transmission electron microscopy, x-ray diffraction, Raman microspectroscopy, and x-ray absorption spectroscopy provides detailed information about the structure/chemistry/performance relationships and how they vary with varying amounts of Ce and Ho in the YBCO films. The microstructure exhibited by both the Ce-doped and the Ho-doped films contains a high density of crystal basal-plane aligned, fluoritelike precipitates within the YBCO matrix. For optimally doped samples, the influence of these nanocrystalline phases on the flux pinning properties manifests itself as a significant improvement in the critical current density (J{sub c}) for magnetic field orientations that approach being parallel to the ab planes of the YBCO, while no appreciable change is observed in either self-field J{sub c} or applied-field J{sub c} performance in the vicinity of field orientations parallel to the YBCO c-axis. The Ce is almost exclusively concentrated in the fluoritelike nanoprecipitates, while the Ho incorporates into both the planar arrays of nanoprecipitates and the superconducting matrix, where it substitutes for Y in the YBCO lattice. The present findings for Ce and Ho doping are in interesting contrast with our prior findings for Zr-doped MOCVD films due to the fact that the Zr-doped films exhibit columnar precipitate arrays that produce a substantial improvement in J{sub c} for magnetic field orientations parallel to the YBCO c-axis, while no appreciable change is observed in either self-field or applied-field J{sub c} performance for field orientations parallel to the ab planes. These results suggest that improvement of the in-field J{sub c} of YBCO films over an extended range of field angles could be achieved by doping strategies that simultaneously produce both ab-plane aligned and c-axis aligned precipitate arrays.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1020704
• Report Number(s): ANL/MSD/JA-70503
• Journal Information: J. Appl. Phys., Journal Name: J. Appl. Phys. Journal Issue: 11 ; Jun. 1, 2011 Vol. 109; ISSN 0021-8979
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTROSCOPY
CHEMICAL PROPERTIES
CHEMISTRY
CRITICAL CURRENT
DEFECTS
DEPOSITION
FABRICATION
MAGNETIC FIELDS
MAGNETIC FLUX
MICROSTRUCTURE
PERFORMANCE
PRECURSOR
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION