Properties of Y-Ba-Cu-O powder prepared by evaporative decomposition of solution for melt-processed bulk ceramics

Y-Ba-Cu-O (YBCO) precursor powder composed primarily of YBa2Cu3O7-delta (Y- 123) and Y2BaCuO5 (Y-211) containing 0.1 w/w% Pt has been prepared by the e vaporative decomposition of solution (EDS) and subsequent calcination for t he fabrication of bulk melt-processed ceramics. The decomposition process i n the as-produced powder and the formation of the Y-123 and Y-211 phases ha ve been studied in detail using differential thermal analysis and powder x- ray diffractometry. The morphology, microstructure and particle size distri bution of the powder has been investigated using scanning electron microsco py, transmission electron microscopy and particle size analysis, and the po wder has been found to contain a significant proportion of sub-micrometre-s ized particles. Samples fabricated by seeded melt growth using the EDS-prep ared powder have been observed to exhibit a finer distribution of the Y-211 phase than is typically obtained in similar samples prepared via a mixed o xide route. This provides direct evidence of the suitability of EDS precurs or powder for the fabrication of large-grain, high-J(c) melt-processed YBCO monoliths.