Patent US4200555A successfully refreshed from Google Patents.
US4200555A
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Low work function hexaboride electron source
Assignee: AT&T Inc
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Filing: 1978-07-27
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Granted: 1980-04-29
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Expires: 1998-07-27
Abstract
Abstract An electron source using an electron emissive material having a composition represented by the nominal atom formula La x (Nd y Pr 1-y ) 1-x B 6 ; x less than 0.5 and greater than 0.2, y less than or equal to 1.0 and greater than or equal to 0.0, is described. The electron source is well suited for use in instruments such as scanning electron microscopes and electron beam exposure systems.
Inventors
- 👤 David C. Joy
- 👤 Paul H. Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:19
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/5156; C04B35/58; C04B35/5805; C30; C30B; C30B13/00; C30B15/00; C30B29/00; C30B29/10; C30B9/00; H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H01J1/148
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
84 words
An electron source comprising an electron emissive material and a mounting structure, said structure supporting said electron emissive material, characterized in that said electron emissive material consists of a composition represented by the nominal atom formula (Z x ) (Nd y Pr 1-y ) 1-x B 6 ; x less than 0.5 and greater than or equal to 0.2, y less than or equal to 1.0 and greater than or equal to 0.0, and Z selected from the group consisting of La and Ce.
Claim 2
Dependent Claim
84 words
An electron source comprising an electron emissive material and a mounting structure, said structure supporting said electron emissive material, characterized in that said electron emissive material consists of a composition represented by the nominal atom formula (Z x ) (Nd y Pr 1-y ) 1-x B 6 ; x less than 0.5 and greater than or equal to 0.2, y less than or equal to 1.0 and greater than or equal to 0.0, and Z selected from the group consisting of La and Ce.
Claim 3
Dependent Claim
13 words
An electron source as recited in claim 1 in which Z is La.
Claim 4
Dependent Claim
14 words
An electron source as recited in claim 2 in which x is approximately 0.3.
Claim 5
Dependent Claim
14 words
An electron source as recited in claim 3 in which y is approximately 1.0.
Claim 6
Dependent Claim
14 words
An electron source as recited in claim 3 in which y is approximately 0.0.
Claim 7
Dependent Claim
24 words
An electron source as recited in claim 3 in which said mounting structure comprises vitreous carbon pieces, said pieces holding said electron emissive material.
Claim 8
Dependent Claim
24 words
An electron source as recited in claim 6 in which said mounting structure further comprises molybdenum jaws, said jaws supporting said vitreous carbon pieces.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |