Method of making lead and bismuth ruthenate and iridate pyrochlore compounds
US4203871A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1978 |
| Grant date | May 20, 1980 |
| Priority date | — |
| Expiry date | Nov 1, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01M12/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A liquid solution method of preparing electrically conductive pyrochlore compounds having the formula: EQU A.sub.2 [B.sub.2-x A.sub.x ]O.sub.7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0.ltoreq..times..ltoreq.1.0 and 0.ltoreq.y.ltoreq.1. The method involves reacting A and B cations to yield a pyrochlore oxide by precipitation of A and B cations in a liquid medium having a pH which is equal to or greater than 4.5, but less than 13.5, in the presence of an oxygen source at a temperature below about 200.degree. C. for a time sufficient for reaction to occur. In those instances in which amorphous reaction products are obtained, these amorphous reaction products are subsequently heat treated at a temperature of about 200.degree. C. to about 600.degree. C. for a time sufficient to convert amorphous reaction products to crystalline pyrochlore(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.