FLUX PINNING CHARACTERISTICS IN
YBa$_{2}$Cu$_{3}$O$_{7}$ WITH COLUMNAR DEFECTS
Title, author, abstract
- title
-
FLUX PINNING CHARACTERISTICS IN
YBa$_{2}$Cu$_{3}$O$_{7}$ WITH COLUMNAR DEFECTS
- authors
-
M. Kiuchi and T. Matsushita
Department of Computer Science and Electronics,
Kyushu Institute of Technology, 680--4 Kawazu, Iizuka 820, Japan
- abstract
-
It was shown that columnar defects nucleated in high
temperature superconductors by heavy ion irradiation work as
strong pinning centers and enhance the irreversibility field
in the high temperature region. In this study, the
characteristics are theoretically investigated for
YBa$_2$Cu$_3$O$_7$ in the magnetic field parallel to both
the columnar defects and the $c$-axis. The normal core
interaction of the columnar defects is assumed for the
elementary pinning force and the statistical summation of
those forces is carried out for the estimation of the
virtual pinning force density in the creep-free case. The
critical current density under the flux creep and the
irreversibility field are numerically calculated using the
flux creep theory. The obtained irreversibility field agrees
well with the experimental results on an
YBa$_{2}$Cu$_{3}$O$_{7}$ single crystal. Discussion is given
on the pinning efficiency by randomly distributed columnar
defects.
- Original paper appears in
-
8th International Symposium on Superconductivity
October 30-November 2, 1995
Hmamatsu, Shizuoka, Japan