This paper demonstrates the details of the vortex dynamics correlated to the penetrated state by means of the evolution of time dependence of voltage $V$ for both at low and moderate dissipation levels. The transport relaxation measurements $\mathrm{}(V-t)\mathrm{}$ have been carried out in a bulk superconducting ${\mathrm{Y}}_1{\mathrm{Ba}}_2{\mathrm{Cu}}_2{\mathrm{O}}_{7-\delta }$ sample as a function of the current (I), temperature (T), and external field (H). It has been observed that the evolution of the $V-t$ data strongly depends on I, T, and H in the investigated regions, and exhibit several interesting features revealing the details of the penetrated state correlated to the motion of flux lines. The unusual data observed in $V-t$ curves have been explained in terms of the plastic flow of the vortices by considering the disorder in the coupling strength between the superconducting grains. In addition, the time evolution of the $V-t$ curves have been discussed in terms of the current and field induced organization of the vortices and it has been shown that the driving current works as an effective temperature by annealing dynamically the corresponding metastable states.

• Received 11 November 2002

DOI:https://doi.org/10.1103/PhysRevB.68.144513