TEXTURING AND TEXTURE-INDUCED INTERGRANULAR CRITICAL-STATE ANISOTROPY OF SUPERCONDUCTING (BI,PB)2SR2CA2CU3OX CERAMICS

Different techniques of texturing superconducting (Bi,Pb)2Sr2Ca2Cu3Ox ceramics, including magnetic alignment, cold-die pressing, unidirectional hot pressing and a combination of these techniques, have been systematically examined with respect to the final microstructures and superconducting properties of the ceramics. The intergranular critical state of the textured ceramics was found to be anisotropic, due to a high degree of grain alignment in these materials. All the intergranular critical states in these materials could be described by the Bean model, although the temperature dependence of the average intergranular pinning force densities were different. The microstructures of the samples were characterized using scanning electron microscopy and bulk density measurement. The critical states of the textured materials were studied using a.c. magnetic susceptometry.