Pj. King et al., THE CURRENT-VOLTAGE CHARACTERISTICS OF SINGLE-CRYSTAL WHISKERS OF 2-2-1-2 BISCCO, Physica. C, Superconductivity, 215(1-2), 1993, pp. 67-76
The current-voltage characteristics of a single-crystal whisker of the
2:2:1:2 phase of bismuth strontium calcium copper oxide have been mea
sured over a wide range of temperatures and magnetic fields. In low ma
gnetic fields there are indications of a phase transition. In higher m
agnetic fields the current-voltage characteristics obey powerful scali
ng relationships. In large fields and low currents we find that the di
ssipation has a number of the characteristics of the thermally activat
ed flux creep (TAFC) model of Kim and Anderson, in particular the temp
erature and magnetic field dependences of the barrier height obey the
typical behaviour for that class of model. However, the flux-bundle pa
rameters must be taken as temperature dependent. At high fields and hi
gh currents the observed behaviour differs very significantly from the
TAFC prediction.