ANALYTICAL TEM INVESTIGATIONS OF YBA2CU3O7-X WITH Y2BACUO5 INCLUSIONS

Melt textured Y-Ba-Cu-O material with inclusions of the expected composition of Y2BaCuO5 was characterized by magnetic measurements (critical current density: 4 X 10(4) A cm(-2) at 77 K, 0 T) and its microstructure was investigated by a combination of transmission electron microscopic (TEM) imaging, electron diffraction and energy dispersive X-ray spectroscopy (EDXS) in the same microscope with an acceleration voltage of 200 kV. With regard to the investigated inclusions and their vicinities it was impossible to find a systematical arrangement of the crystallographic orientations of matrix and inclusion. On the other hand there are indications that the disturbed transition width depends on the crystallographic orientations of matrix and inclusion referring to the interface between them. Therefore a wide spread of transition widths up to some nanometers is probable. The smallest interface width observed in a micrograph was less than 1 nm.