Process for the preparation of a semiconductor from an oxalate
US5457088A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 7, 1990 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Sep 7, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/738
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
To prepare a phase-pure, ceramic oxide superconductor which contains, in addition to copper, at least one alkaline earth metal from the group comprising Ba, Sr and Ca, and at least one metal from the group comprising Y, La, Tl, Pb and the rare earths, for example of YBa.sub.2 Cu.sub.3 O.sub.7-x, a solution is prepared which contains the metal components in the atomic ratios of the superconductor. The metals are precipitated as oxalates by combining this solution with an oxalic acid solution, the mixture of the oxalates is separated off, dried and decomposed to form the oxides, and the latter are subsequently sintered at temperatures of from 700.degree. to 900.degree. C. in the presence of oxygen to form the superconductor. In this process, the heating of the metal oxalates and the oxides formed therefrom up to 700.degree. C. is carried out at a maximum oxygen partial pressure of 50 mbar, preferably in an inert gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.