Oxide cathode
US4904897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1984 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Dec 4, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J1/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An oxide cathode comprising a base 1 which consists substantially of titanium and a heater element 5 coated with aluminium oxide 6 to heat the base 1, which bears a porous alkaline earth metal oxide emissive layer 4. When the surface of the titanium base 1 which is opposed to the heater element 5 bears a metal layer 7 consisting at least of one of the metals Pt, Mo, Ta and W, a solution is obtained to the problem occurring in titanium cathodes in that titanium in contact with aluminium oxide is not chemically stable. The metal layer preferably consisits of pure tungsten and is formed by chemical vapour desposition (CVD). The metal layer is preferably from 1 to 10 .mu.m thick.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.