Abstract
Magnetic hysteresis loops are measured on Bi 2 Sr 2 CaCu 2 O 8+δ (Bi-2212) single crystal with different surface states and shapes. The result obtained on Bi-2212 single crystals with dirty and clean surfaces demonstrates that variation of surface state does not result in the disappearance of anomalous magnetization peak H 2p and has only an influence on the width of magnetic hysteresis loops. The result obtained on Bi-2212 single crystals with elongated and circular shapes shows that the variation of shape also does not give rise to the disappearance of H 2p . The origin of H 2p of Bi-2212 single crystal is suggested to originate from other intrinsic reasons and should not be attributed to the surface state and surface shape. © 2002 Elsevier Science B.V. All rights reserved.