CRITICAL-CURRENT DENSITY AND MICROSTRUCTURE OF SCREEN-PRINTED (BI,PB)2SR2CA2CU3OX THICK-FILM SANDWICHED BETWEEN AG SUBSTRATES

A process of combined rolling and uniaxial pressing with intermediate sintering steps for fabrication of screen-printed (Bi,Pb)2Sr2Ca2Cu3Ox thick films sandwiched between Ag substrates yields c-axis-oriented microstructures with a high critical current density (J(c)) of 1. 5 X 10(4) A/CM2 (77 K, 0 T) and 9.0 X 10(4) A/cM2 (23 K, 0 T). The measured J(c) anisotropy at 77 K, as a function of the angle theta between B and c axis, is pronounced. An increase in B sharpens a peak at theta = 90-degrees (i.e., B perpendicular to c) in the J(c) vs theta curve, together with enhancement of the anisotropy ratio defined as J(c)(B perpendicular to c)/J(c)(B parallel-to c). In high fields above 0.5 T, the half-height angular width of the peak approaches an average misalignment angle (4-degrees-6-degrees) between the grains with increasing B.