STRUCTURAL AND ELECTRONIC ANISOTROPY IN POLYCRYSTALLINE COMPACTIONS OF THE HIGH-TC SUPERCONDUCTOR EUBA2CU3O7-DELTA

X-ray diffraction studies show that simple cold-pressing of EuBa//2Cu//3 O//7// minus // delta polycrystalline compactions, as practiced by numerous researchers, leads to very large microstructural anisotropy, with the crystallographic c axis preferentially oriented parallel to the axis of pressing. As shown by variable-temperature resistivity and thermoelectric power measurements, the direction of greatest metallic character at temperatures above the superconducting transition temperature is that perpendicular to the pressing direction. A tentative analysis using a Hubbard/Heikes approach yields an average copper oxidation state in good agreement with experiment.