Abstract
The vortex phase diagram in is investigated by studying the linear ac transverse permeability axis) in a wide range of temperature and magnetic fields. At low fields superconducting phase coherence in the direction shows that the ordered vortex solid state is characterized by a -axis vortex correlation length limited by the sample thickness . At low temperatures point disorder is sufficiently strong and the phase coherent ordered vortex solid becomes metastable. In the temperature range when the applied field exceeds , the ordered vortex state transforms into an entangled state with no indication of reduction of At a higher crossover field the linear response becomes Ohmic, . At higher temperatures the vortex structure becomes an uncorrelated vortex liquid in all directions.
- Received 8 August 1997
DOI:https://doi.org/10.1103/PhysRevB.57.3663
©1998 American Physical Society