ROLE OF ELECTROMAGNETIC COUPLING IN THE LOW-FIELD PHASE-DIAGRAM OF BI2.15SR1.85CACU2O8+DELTA

A detailed study has been made of a transition in the flux lattice of the superconductor Bi2.15Sr1.85CaCu2O8+delta using the technique of mu on-spin rotation. The results are in excellent agreement with a recent theoretical analysis on the low-field phase diagram of highly anisotr opic Superconductors. In particular, the important role of electromagn etic interactions between vortex segments is demonstrated. The form of the phase boundary suggests that the transition may be identified wit h a simultaneous melting and decoupling of the vortices in adjacent la yers.