Microstructure, texture and superconducting properties of Bi2212 ceramics, deformed by torsion under pressure

A systematic investigation of the effect of high-temperature deformation by torsion under quasi-hydrostatic pressure on the microstructure, texture and superconducting properties of Bi2212 ceramics was carried out. Intercolony sliding was identified as the main mechanism of plastic deformation and basal texture formation. In all investigated deformation regimes the colony thickness did not change, only their length varied. The superconducting properties were analyzed as caused by the action of three main pinning centers: intracolonial lattice defects, low-angle colony boundaries and particles of secondary phases which appear during the decomposition of the Bi2212 phase near the melting point.