Bitter pattern study of flux distribution in the BSCCO (2212)

Microstructures of flux lines (FL) in Bi2Sr2CaCu2O8 single crystals are obs erved by a high-resolution Bitter-decoration technique. Experiments were pe rformed at low (4.2 K) and high (77 K) temperatures under a constant magnet ic field of 20 G. We could observe the interaction between FL and defects o f materials, such as growth steps and other planar crystal defects. FL near defects were remarkably different between low and high temperatures. We al so found that planar crystal defects. which extended parallel to the a-axis , were only active at low temperatures. (C) 2001 Elsevier Science B.V. All rights reserved.