Title :
Flux motion dynamics and self-organized criticality in YBCO thin films
Author :
Yu, L.K. ; Yeh, W.J. ; Kao, Y.H.
Author_Institution :
Dept. of Phys., Idaho Univ., Moscow, ID, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
The analytical approximated result of the flux noise in mixed state under the current driving force is derived. The Anderson-Kim flux creep model is used to relate this noise to the current density. The numerical result is then compared with the flux noise data obtained from YBCO thin films measured with a DC SQUID. Using this method, we can estimate the free energy U/sub 0/ and the bundle size. The invariance of the noise peak position with the detecting coil distance indicates that the configurations of the moving bundles are space invariant so the system is in a self-organized criticality state.<>
Keywords :
barium compounds; flux creep; free energy; high-temperature superconductors; magnetic noise; superconducting thin films; yttrium compounds; Anderson-Kim flux creep model; DC SQUID; YBCO thin films; YBa/sub 2/CuO/sub 7/; bundle size; coil distance; current density; current driving force; flux motion dynamics; flux noise; free energy; mixed state; self-organized criticality; space invariant; Bridges; Creep; Physics; SQUIDs; Sputtering; Superconducting coils; Superconducting device noise; Temperature sensors; Transistors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
