MICROSTRUCTURE AND MAGNETIZATION J-C OF THE BULK Y-BA-CU-O SUPERCONDUCTOR PREPARED BY THE INFILTRATION-REACTION PROCESS

Y-Ba-Cu-O superconductors were prepared by the infiltration-reaction process. Y2BaCuO5 (''211'') powder compact was placed on the top of YBa2Cu3Ox (''123'') powder compact and heat treated at 1030 degrees C. The liquid appearing in the ''123'' compact infiltrated into the ''211'' compact and the peritectic reaction occurring during cooling resulted in the dispersion of fine ''211'' particles in the ''123'' grains without residual liquid phase. The specimen with 35 vol.% of 211 particles prepared by this method showed uniform distribution of 211 particles and a much higher pinning effect that the conventionally melt-grown specimen. By infiltrating the liquid into a hot-pressed ''211'' body, the volume fraction of the ''211'' particles could be increased up to 80%. The magnetization J(c) of the specimen was determined and related to its microstructure.