Characteristics of micro-texture and meso-texture in (Bi, Pb)₂Sr₂Ca₂Cu₃O₁₀ superconducting tapes

Grain boundary misorientation is known to limit the critical current density of bulk high temperature superconductors. However, the effect of mechanical deformation on the texture evolution during powder-in-tube (PIT) processing remains unclear, especially on the microstructural level. In the present work, the micro- and meso-texture characteristics of PIT-processed (Bi, Pb)₂Sr₂Ca₂Cu₃O₁₀ (Bi2223) superconductor tapes were investigated. The results for micro-texture show that a/b-axes texture does exist in PIT-processed tapes. From the meso-texture studies, it was found that a majority of the grain boundaries were formed by grains with a non-parallel c-axis. These grain boundaries generally have low mismatch angles of up to ~10°. High-angle misorientation boundaries ranging up to 45° are generally c-axis twist boundaries. Furthermore, about 40% of the grain boundaries could be coupled strongly.