The formation and distribution of texture microstructure produced by mechanical deformation in silver-sheathed BSCCO superconductors

Abstract

Mechanical deformation and subsequent thermal treatment have been widely used in BSCCO superconductor processing. The purposes of this treatment include introducing texture microstructure, obtaining desired phases and healing the microcracks. It has been shown that most supercurrent flows through the thin layer of superconductor next to the silver sheath. It was proposed that this was related to the good grain alignment in this area. However, the effects of mechanical deformation on the formation and distribution of the texture microstructure in BSCCO superconductors have not been fully understood. The present paper reports a detailed study of the relationships between the mechanical deformation and texture distribution in the BSCCO tapes. Results indicate that the texture distribution behaviours in Bi2223 and Bi2212 are different. Mechanical deformation produces a stronger texture and deeper texture distribution in Bi2223 than in Bi2212. Based on the experimental results, the formation mechanisms of the texture microstructure during mechanical deformation are discussed.