Author
McElfresh M,
Miller TG,
Schaefer DM,
Reifenberger R,
Muenchausen RE,
Hawley M,
Foltyn SR, and
Wu XD.
Institution
Dept. of Phys. Purdue Univ., West Lafayette, IN, USA.
Title
Correlation of surface topography and flux pinning in superconducting YBaCuO
films.
Source
Journal of Applied Physics, vol.71, no.10, 15 May 1992, pp.5099-102. USA.
Abstract
The surface topography of YBa/sub 2/Cu/sub 3/O/sub 7/ thin films prepared by
pulsed laser deposition is studied by atomic force microscopy and scanning
tunneling microscopy. The possible contributions from observed structural
features to the critical current density J/sub c/ are discussed. It is shown
that the contribution of the screw dislocations associated with some
structures can be either repulsive or attractive, depending on the dominant
pinning mechanism. At low magnetic fields (to about 0.26 kOe) these
dislocations can account for the observed critical current density values
(J/sub c/>10/sup 11/ A/m/sup 2/) while for larger fields the higher-density
steplike growth structures can account for significant values of J/sub c/. It
is shown that the pinning strength associated with pinning at steps varies
inversely with thickness. (26 References).