Junction between hexaboride-containing and tantalum-containing components
AssigneeFEI Company
InventorsKun Liu, Joshua Mutch
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Abstract
Apparatus and methods are disclosed for a mechanically stable, long-life junction between hexaboride-containing and tantalum-containing components. Examples are used as a cold field emitter assembly which is compatible with ultra-high vacuum and occasional high-temperature flashing. A metal adapter is welded to a hexaboride electrode. Some embodiments use a tantalum adapter and a LaB6 microrod electrode with a nanorod emitter tip. Other material combinations are disclosed, as also usage in electron sources for electron microscopes. In variations, the adapter is deposited onto a filament and the electrode then welded to the adapter.
Claims20
An emitter assembly, comprising:
- a first component comprising a rare-earth hexaboride;
- a second component comprising at least 80 at % tantalum;
- and
- a zone between the first component and the second component, the zone comprising an admixture of the rare-earth hexaboride and tantalum.
A method, comprising:
- forming, using non-contact energy delivery, a zone between a first component comprising a rare-earth hexaboride, and a second component comprising at least 80 at % tantalum, wherein the zone is an admixture of the rare-earth hexaboride and tantalum.
An electron source, comprising:
- a first component comprising a rare-earth hexaboride;
- a second component comprising tantalum;
- a third component comprising tungsten or rhenium;
- a first fusion zone between the first component and the second component, the first fusion zone comprising an admixture of the rare-earth metal hexaboride and tantalum;
- and
- a second fusion zone between the second component and the third component.
Dependencies are inferred from the claim text.