Anomalous peak effect in single crystal Bi2Sr2CaCu2O8+y studied by Hall probe magnetometry

Abstract

We have studied an anomalous peak effect in a Bi2Sr2CaCu2O8+y single crystal using a specially designed Hall probe magnetometer. In order to investigate the origin of the anomalous peak effect which manifests itself in the magnetic hysteresis loop, the relaxation (10-2 s<t<104s), and the local field imaging experiments were performed. Decoupling of 2D vortices in neighboring CuO layers, namely, a dimensional crossover in the pinning mechanism, is proposed as a possible mechanism of the peak effect.