1. Eliminating thickness dependence of critical current density in YBa2Cu3O7-x films with aligned BaZrO3 nanorods.
- Author
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Xiang Wang, Baca, F. Javier, Emergo, Rose L. S., Wu, Judy Z., Haugan, Timothy J., and Barnes, Paul N.
- Subjects
DENSITY ,MAGNETIC fields ,STEREOLOGY ,ELECTRIC currents ,MATERIALS ,CRITICAL currents ,SUPERCONDUCTIVITY - Abstract
The thickness dependence of critical current density (J
c ) has been investigated in YBa2 Cu3 O7-x films with BaZrO3 (BZO) nanorods (YBCO/BZO) aligned along the film normal. With the presence of linear defects in the YBCO/BZO films, the thickness dependence of Jc becomes negligible at self field and weak applied magnetic field (H), suggesting these linear defects playing a key role to the elimination of the thickness dependence of Jc . The effect of temperature (T) and H on Jc thickness dependence have been investigated and comparisons have been made between YBCO and YBCO/BZO samples. Since BZO nanorods alignment is greatly influenced by growth temperature, the quantitative difference in terms of nanorod's density and average length is reflected on Jc angular dependence of H and Jc thickness dependence as thermally assisted flux motion (TAFM) becomes important above a threshold H determined by the BZO nanorod density. With further increasing H, a monotonically increasing Jc vs. thickness trend was observed in YBCO/BZO films, in contrast to an opposite trend when collective pinning is dominant. This result suggests the thickness dependence of Jc is dictated by the microstructure and hence pinning mechanism in YBCO films. [ABSTRACT FROM AUTHOR]- Published
- 2010
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