Vacuum Bulk Processing of the High-T, Y-Ba-Cu-0 Superconducting Oxides

Nae-Lih Wu；Sern-Hau Lin；Hsi-Her Zern；Chi-Liang Chen

Chinese Journal of Physics

34卷2S期（1996 / 04 / 01）

552 - 560

英文

While vacuum technology has routinely been employed for making the high-T, superconducting oxide thin films, it has not until recently begun to draw increasing attention in the bulk processing. Processing of the high-T, superconducting oxides under greatly reduced oxygen pressure achieved by partial vacuum has been demonstrated not only to increase the process flexibility but, more importantly, also to produce unique properties, such as improved phase purity, better controlled microstructures and superior superconducting properties, for the polycrystalline high-T, oxides. Two examples involving vacuum bulk processing of YBa2Cu3O7-r (the 123 oxide) to give, respectively, the 123 powder with narrowly distributed particle sizes and the melt-grown 123/Ag bulk and tape composites are described. The associated themmodynamic and kinetic behaviors with these processes are reviewed.