A study has been carried out on the vortex liquid state of (formula presented) single crystal with excessive-oxygen doping based on its magnetotransport data. The enhanced disorder and reduced anisotropy due to excessive oxygen content are shown to give rise to the (formula presented) behavior for the activation energy of thermally assisted flux flow (TAFF), observed in the Bi-based system. This study has also revealed the existence of high and low-TAFF regimes supporting a previous report on the existence of a theoretically predicted disentangled vortex line liquid phase.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2003