Phase growth and microstructure modifications induced by annealing in highly textured superconducting Bi-2212 thin rods

Bi-2212 cylindrical rods were obtained using a laser-induced directional so lidification system. Although as-grown Bi-2212 samples are well textured, t hey do not exhibit superconducting behavior and, as a result, need further heat treatments. The modifications taking place during annealing were analy zed in the present work, in particular with respect to the evolution of the microstructure with the annealing time and the phase content. Diffusion pr ocesses in which the Bi-2212 phase grows along the thickness of the platele ts take place during annealing. The presented results show that the physica l properties of these samples improve during the initial approximately 60 h of annealing and that they remain constant thereafter.