Abstract
The properties of grain boundaries at microwave-frequencies in the high-TC materials are of interest for both practical applications and basic physics. We report the measurements of intermodulation distortion (IMD) in engineered grain boundaries in YBCO films fabricated on sapphire bicrystals with misorientation angles of 0, 2, 5, 7.5, 10 and 24°. The measurements indicate that low-angle grain boundaries are not the source of IMD in epitaxial films. We also report the microwave response of YBCO 24° bicrystal grain-boundaries to small dc magnetic fields, from 0 to 10 Oe. Peaks in the microwave loss as high as 5 times the baseline values at certain dc magnetic fields are observed. The losses result from individual Josephson vortices penetrating into the grain-boundary which is modeled as a long Josephson junction. Excellent quantitative agreement between the experimental data and the model has been obtained for the case of the increasing field.
Original language | English (US) |
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Pages (from-to) | 2804-2807 |
Number of pages | 4 |
Journal | IEEE Transactions on Applied Superconductivity |
Volume | 11 |
Issue number | 1 III |
DOIs | |
State | Published - Mar 1 2001 |
Externally published | Yes |
Event | 2000 Applied Superconductivity Conference - Virginia Beach, VA, United States Duration: Sep 17 2000 → Sep 22 2000 |
Keywords
- Grain boundaries
- Nonlinear surface impedance
- Vortex dynamics
- Y-Ba-Cu-O thin films
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering