YBCO was synthesized by the co-precipitation of stoichiometric amounts of nitrate solutions of Y, Ba and Cu using a mixture of NaOH, Na2CO3and H2C2O4in a molar ratio of 5:1:1 as a precipitation agent. Even after prolonged thermal treatment at 950 °C the samples exhibit a zero-resistance critical temperature of about 87 K. This fact indicates a copper deficiency of about 0.1, more reduced than in the case of hydroxycarbonate co-precipitation. The as-synthesized samples have a high density, reaching 94% of the theoretical density. The SEM analyses show a large grain distribution from microns to tens of microns, favourable for good stacking. © 1997 Academic Press Limited.
|Pages (from-to)||273 - 277|
|Number of pages||5|
|Journal||Superlattices and Microstructures|
|Publication status||Published - Apr 1997|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics