Characterization of microtexture in Bi-2223 tapes using electron back-scatter pattern orientation imaging

摘要

Automated orientation measurements using electron back-scatter pattern analysis have been taken on samples of (BiPb)_2Sr_2Ca_2Cu_3O_x (Bi-2223) tapes produced using the powder-in-tube method. A strong c-axis fibre texture was found, with almost 90 percent of the Bi-2223 material having a crystal direction normal to the tape surface within 10 deg of [001]. The intensity along the fibre texture was found to be almost random, in contrast to some previously reported investigations. An analysis of the misorientations between adjacent plates revealed strong correlations. The measured misorientation angle and axis distributions were compared against those for random pairs of orientations corresponding to the same overall texture, revealing a preference for low angle misorientation boundaries, and a preference for misorientation axes to lie along [010]-[110] for low (<20 deg) misorientation angles. Although many plates are tilted with respect to the tape surface, the majority of the boundary area per unit volume is more twist than tilt in character.