Transmission electron microscopy investigation of Bi-based HTS tapes

Abstract
Bi(Pb)-2223/Ag powder in tube tapes have been examined by TEM. The tapes show good alignment and phase purity in the SEM but TEM investigations revealed a number of fine-scale, current-limiting, features, Such features include variation in grain boundary structure, amorphous phases at twist grain boundaries, residual 2212 layers present at grain boundaries and inside grains, and secondary phases, The Ag/superconductor interface has been shown to be relatively planar with no amorphous phases with the Bi(Pb)-2223 having near perfect c-axis alignment at the interface