10.25358/DSPACE-DEV-71389
Miu, Dana
Miu, L.
Jakob, Gerhard
Adrian, Hermann
Relaxation of remnant magnetisation in YBa2Cu3O7−δ films
Johannes Gutenberg-Universität Mainz
2007
530 Physik
530 Physics
Johannes Gutenberg-Universität Mainz
Johannes Gutenberg-Universität Mainz
2020-03-12
2020-03-12
2007
Physica : C. Bd. 460-462. S. 1243 - 1244
https://dspace-dev.ub.uni-mainz.de/handle/20.500.12030/124439
The relaxation of the remnant magnetisation in optimally doped disk-shaped YBa2Cu3O7−δ films with the initially applied magnetic field H oriented along the c axis was measured using dc SQUID magnetometry. The temperature (T) dependence of the experimentally observed normalised magnetisation relaxation rate S exhibits three distinct regions. At high T, S(T) increases with increasing T, which can be explained in terms of plastic vortex creep. The well known plateau in the S(T) variation at intermediate T appears to be caused by collective (elastic) creep in a dynamically ordered vortex system. At low T, where S increases again with increasing T, the magnetisation relaxation is not in a pure thermally activated flux-creep regime, due to the occurrence of micro-flux jumps. This seems to be the origin of the recently proposed exponential current density dependence of the effective vortex pinning potential.