Texturing of Micaceous Superconductor Powder and Fabrication of Wire to Preserve the Texture

The Bi-based high-temperature superconductors are micaceous: grains cleave preferentially in the ab plane when fractured, so that powders consist of thin platelets. Superconducting current transport is similarly planar, and supercurrent flow is largely limited to the ab plane. We report studies of two methods to align the particles of such powder in a thin layer so that most particles are aligned with parallel ab planes. We are developing a `jelly-roll' method for wire fabrication that could preserve this desirable texture.