EVIDENCE FOR 3-DIMENSIONAL FLUX-CREEP IN THIN-FILM BI2SR2CACU2O8+DELTA

We have measured sweep-fate dependent magnetization hysteresis curves of thin-him Bi2Sr2CaCu2O8+delta using a Hall probe magnetometer in an unconventional geometry. We find a structure in the response well belo w the three-dimensional to two-dimensional crossover field. The observ ed strong enhancement of the perpendicular held component's creep fate in the presence of an in-plane applied magnetic held is in contrast t o recent findings. We attribute this to the existence of a finite corr elation length between vortex pancakes along the held direction larger than the interlayer spacing leading to a three-dimensional behavior o f flux lines in Bi2Sr2CaCu2O8+delta at 77 K.