Anomalous magnetization in a heavily Pb-doped Bi2Sr2CaCu2O8+δ as-grown single crystal

Anomalous magnetization is investigated on a heavily Pb-doped Bi2Sr2CaCu2O8+δ as-grown single crystal [(Bi,Pb)-2212] with Tc=92 K. Both the anomalous magnetization peak H2p and the onset of the anomalous magnetization peak Hon are detected in temperature region from 0.3Tc to 0.9Tc 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 Tc. The temperature dependence of H2p 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