STRUCTURE, MICROSTRUCTURE, MAGNETIC-PROPERTIES AND CHEMICAL-STABILITYOF HOBA2SBO6 WITH YBA2CU3O7-DELTA SUPERCONDUCTOR

A complex perovskite oxide HoBa2SbO6 in the Ho-Ba-Hf-O, rare-earth bas ed oxide system, has been synthesised and sintered as a single phase m aterial. The structure, microstructure, quantitative elemental analysi s and magnetic properties of this material have been studied by X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-r ay (EDX) techniques and magnetic susceptibility measurements. Signific ant presence of superstructure reflection lines in the XRD spectra of HoBa2SbO6 reveals that it is an ordered complex perovskite oxide. Magn etic susceptibility measurements show that HoBa2SbO6 presents a parama gnetic behaviour at low temperature (5-300 K). Microstructure and EDX analysis show that sintered HoBa2SbO6 has homogeneous surface morpholo gy with uniform particle size (1-2 mu m) distribution and there is no evidence of impurity in the single phase sintered HoBa2SbO6. The chemi cal stability of HoBa2SbO6 with YBa2Cu3O7-delta superconductor was stu died. This study shows that HoBa2SbO6 is chemically compatible with YB a2Cu3O7-delta and it did not have deleterious effect on the supercondu cting transition temperature of YBa2Cu3O7-delta. Also, HoBa2SbO6 melts congruently and single crystals could be grown from the melt. In view of these favourable characteristics, HoBa2SbO6 could be used as a pot ential substrate material for YBa2Cu3O7-delta superconductor film. (C) 1998 Published by Elsevier Science B.V. All rights reserved.