Growth of the superconducting phase in ceramic Y1.2Ba0.8CuOy samples

Abstract
Differently prepared samples with the nominal composition Y1.2Ba0.8CuOy are examined via microscopy, energy dispersive x‐ray analysis, x‐ray diffraction, and measurements of resistivity and susceptibility. Various phases are identified directly. Essentially these are Y2BaCuO5, which forms a matrix with semiconducting and antiferromagnetic properties and YBa2Cu3O7−x, which is present in a dendritic morphology. The dendritic appearance indicates that YBa2Cu3O7−x is formed by nucleation and growth during sintering. Despite the particular growth mechanism of sintered materials a strong analogy exists with dendritic growth during solid‐state transformations in metallic alloys.