Critical current density and dynamical relaxation rate below the matching field in thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}

The authors studied the superconducting current density j{sub s}(B, T) and dynamical relaxation rate Q(B, T) of laser ablated thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} with various dislocation densities (n{sub disl} {approximately} 7--70 {micro}m{sup {minus}2}). In these films dislocat...

Full description

Saved in:
Bibliographic Details
Published in:Journal of low temperature physics 1999-12, Vol.117 (5-6)
Main Authors: Klaassen, F.C., Doornbos, G., Huijbregtse, J.M., Dam, B., Griessen, R.
Format: Article
Language:English
Subjects:
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
CURRENT DENSITY
DISLOCATIONS
HIGH-TC SUPERCONDUCTORS
MAGNETIC FLUX
MATERIALS SCIENCE
RELAXATION
SUPERCONDUCTING FILMS
YTTRIUM OXIDES
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The authors studied the superconducting current density j{sub s}(B, T) and dynamical relaxation rate Q(B, T) of laser ablated thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} with various dislocation densities (n{sub disl} {approximately} 7--70 {micro}m{sup {minus}2}). In these films dislocations act as strong pinning centers like columnar defects in heavy ion-irradiated crystals. The matching field clearly manifests itself in a constant j{sub s}(B) {approximately} 5{center{underscore}dot}10{sup 11}--1.{center{underscore}dot}10{sup 12} Am{sup {minus}2} at T = 4.2 K and {mu}{sub 0}H {approx{underscore}lt} 0.7{center{underscore}dot}B{sub {Phi}} and a constant Q(B). In contrast to irradiated crystals, in films they do not observe a peak in the relaxation rate Q versus T below the matching field B{sub {Phi}} {identical{underscore}to} n{sub disl}{center{underscore}dot}{Phi}{sub 0}. Instead, in thin films Q(T) increases monotonously with increasing temperature. They conclude that the influence of vortex-vortex interactions in thin films is greatly reduced due to the non-random distribution of pinning sites and the low matching field.
ISSN:0022-2291
1573-7357
DOI:10.1023/A:1022591027514