Granularity in superconductors: intrinsic properties and processing-dependent effects

This contribution presents a selected set of results, obtained as part of a systematic investigation, evidencing that many effects exhibited by superc onductors are distinct manifestations of granularity which, in turn, is env isaged as a break of symmetry. The Wohlleben effect, the "fishtail anomaly" , the magnetic remanence exhibited by Josephson junction arrays, and the ju mps on the magnetic moment of superconducting samples of mesoscopic dimensi ons, are examples which we briefly review and discuss taking granularity as the basic ingredient. The emphasis of the present approach is to recognize the importance of granularity in every scenario intended to explain the ma gnetic properties of superconducting systems. (C) 2001 Elsevier Science B.V . All rights reserved.