Abstract
Anomalous magnetization is investigated on a heavily Pb-doped Bi 2 Sr 2 CaCu 2 O 8+δ as-grown single crystal [(Bi,Pb)-2212] with T c =92 K. Both the anomalous magnetization peak H 2p and the onset of the anomalous magnetization peak H on are detected in temperature region from 0.3T c to 0.9T c based on the descending field branch of magnetic hysteresis loops. At low temperatures below 20 K, the magnetic hysteresis loop behaves as an obvious asymmetry. The double magnetic hysteresis behavior is observed at high temperatures close to T c . The temperature dependence of H 2p can be described according to the thermal disorder induced decoupling theory. The double magnetization behavior may be ascribed to the existence of intra-grain granularity due to the inhomogeneity of oxygen distribution induced by heavily Pb-doping. © 2002 Elsevier Science B.V. All rights reserved.