Preparation and Electrical Characterization of Melt Textured 2212 Bi-Sr-Ca-Cu-Oxide Layers on Ag-Tape

Abstract

Screen printed pastes and Doctor blade processed green tapes prepared from Bi₂Sr₂CaCu₂O₈ powder were subjected to a melt-texturing process on silver foil. Melting and crystallization temperatures were determined using DTA analysis. Highly textured layers were formed by slow cooling from the melting temperature to the crystallization temperature and quenching after a holding period. At 4.2 K and 77 K critical transport current densities j _c as high as 1.3 × 10⁵ A/cm² and 1.1 × 10⁴ A/cm², respectively were obtained in zero field. These values are in good accordance with critical current densities j _cm determined by magnetization measurements. j _c‖ (B ‖ tape) can be related to j _c⊥ (B ⊥ tape) assuming that the field component B ‖ c-axis alone controls j _c (B,T). The analysis results in an average misorientation of the c-axes of the grains of about six degrees. This is directly confirmed by SEM micrographs.