c-axis correlated pinning behavior near the irreversibility fields

摘要

The authors found that the peak at the parallel external field (B‖c) to the c axis in the angular dependence of J_c shrinks and almost disappears with increasing a magnetic field but it grows again with further increasing of a magnetic field at various temperatures for high-J_c Sm_(1+x)Ba_(2-x)Cu_3O_y films. These behaviors can be explained by the flux pinning properties of the interstitial vortices, which locate in between the vortices pinned by the c-axis correlated disorders. From the obtained experimental results, the collective correlated pinned glass state is proposed in a high field region in the vortex glass states.