THERMALLY ACTIVATED FLUX DISSIPATION IN C-AXIS-ORIENTED YBA2CU3O7 PRBA2CU3O7 MULTILAYERS/

We have systematically studied the resistive transition of multilayers of YBa2Cu3O7/PrBa2Cu3O7 (YBCO/PBCO) under different perpendicular mag netic fields. It was found that the resistive transition is dominated by the flux-thermal-activation process; the broadening of the resistiv e transition was observed with the same order as that in single-layer thin films and the resistivity obeys the relation rho=rho0 exp(- U/kT) . The activation energy depends logarithmically on the applied magneti c fields and decreased linearly with temperature. This phenomenon may be attributed to the creation of edge-dislocation pairs in the two-dim ensional pancake vortices situated in the individual YBCO layer. The p ossible pinning mechanisms in the multilayers are discussed.