CRITICAL-CURRENT ANISOTROPY OF HIGH-T-C CERAMICS IN MAGNETIC-FIELD

We discuss the angular dependence with respect to the direction of app lied magnetic field for the critical current j(c) in superconducting c eramics. A simple weak-link network model accounting for the current p aths geometry is analyzed. The j(c) anisotropy is shown to stem from t he difference in the sets of intergranular contacts playing the domina nt role for transport current flowing parallel and perpendicular to ma gnetic field, respectively. The factors determining field and temperat ure dependence of the j(c) anisotropy are studied.