THE NONTRIVIAL DISPERSION OF Y2BACUO5 PARTICLES TRAPPED IN THE YBA2CU3O7-X CRYSTAL MATRIX

Micrographs of melt-textured YBa2Cu3O7-x/Y2BaCuO5 composites (123/211) have been digitized. Through image analysis, we point out that the di spersion of the 211 particles is highly inhomogeneous in the melt and in the 123 crystal matrix. Indeed, free 211 particle regions and 211 a ggregates are observed. The distribution laws are given. Moreover, the dispersions of 211 particles in the melt and those trapped in the cry stal matrix are quite different. We point out that this difference can not be explained solely by the partial dissolution of the 211 particle s during the growth process.