FORMATION OF BI-2212 SUPERCONDUCTING WHISKERS FROM MELT-QUENCHED BSCCO CONTAINING ALUMINA

Bi-Sr-Ca-Cu-O (BSCCO) superconducting whiskers (2212 phase) were prepa red by heating in air the compacted specimens of the mixtures of melt- quenched Bi2SryCa2Cu4Al1Ox powders and alumina powders. Formation of t he whiskers depends on the composition and the applied pressure of the compacts. The optimum composition of the melt-quenched products for p reparing the long whiskers is Bi2Sr2Ca2Cu4Al1Ox. Superconducting whisk ers <1 mm in length (2212 phase) containing an excess amount of copper were grown numerously from the specimen compacted at 20 MPa; long whi skers (2212 phase) of 1-5 mm in length were obtained from that compact ed at 180 MPa. These whiskers showed diamagnetic signals below T(c) co ngruent-to 80 K.