Claims
- 1. A method for coating a carbon velvet material attached to a cathode to make a field emission cold cathode, comprising:
forming a solution of a low work function cesiated salt and de-ionized water; spraying the carbon velvet material with the cesiated salt solution to form a coated carbon velvet material; baking the coated carbon velvet material at a temperature of at least 100° C. for approximately an hour in a vacuum oven evacuated to less than 1 torr.; and venting the vacuum oven to an atmospheric pressure using dry nitrogen.
- 2. A coating method as recited in claim 1, wherein the spraying step includes pressurizing a spraying means with dry nitrogen.
- 3. A coating method as recited in claim 1, wherein the cesiated salt is selected from a group consisting of cesium tellurate and cesium bromide.
- 4. A coating method as recited in claim 1, wherein the steps of forming, spraying, baking, and venting are repeated until a film of cesiated salt having a thickness of 1 angstrom to 10 microns is formed on each of a plurality of shafts of the carbon velvet material.
- 5. A method of making a field emission cold cathode, comprising:
forming a solution of a cesiated salt; coating a carbon velvet material with the cesiated salt solution; and bonding the carbon velvet material to a cathode.
- 6. A method as recited in claim 5 wherein the carbon velvet material is comprised of shaft having tips, and the coating step coats only the tips with the cesiated salt solution.
- 7. A method as recited in claim 5 wherein the carbon velvet material is comprised of shafts, and the coating step coats a plurality of the shafts with a film of cesiated salt having a thickness of 1 angstrom to 10 microns.
- 8. A method of making a field emission cold cathode, comprising:
depositing a vaporized cesiated salt solution onto fibers of a carbon velvet material; forming cesiated salt crystals on the fibers; and bonding the carbon velvet material to a cathode.
- 9. A method as recited in claim 8 wherein the solution includes de-ionized water and the forming step is comprised of evaporating the de-ionized water.
- 10. A method as recited in claim 9 wherein the fibers have tips, and the cesiated salt crystals are formed only on the tips.
- 11. A method of making a field emission cold cathode, comprising:
forming a film of cesiated salt having a thickness of 1 angstrom to 10 microns on each of a plurality of shafts of a carbon velvet material; and bonding the carbon velvet material to a cathode.
- 12. A method as recited in claim 11 wherein the shafts have tips, and the film is formed only on the tips.
- 13. A method of making a field emission cold cathode comprising:
attaching a carbon velvet material having fibers to a cathode; dipping the fibers in a molten cesiated salt solution; and cooling the solution while the fibers are immersed in the solution.
- 14. A method as recited in claim 13 wherein the fibers have tips, and only the tips are dipped in the molten cesiated salt solution.
- 15. A method of making a field emission cold cathode comprising:
attaching a carbon velvet material having fibers to a cathode; dipping the fibers in a molten cesiated salt solution; removing the fibers from the solution; and cooling the fibers after the fibers have been removed from the solution.
- 16. A method as recited in claim 15 wherein the fibers have tips, and only the tips are dipped in the molten cesiated salt solution.
- 17. A method as recited in claim 15 wherein the steps of dipping, removing and cooling are repeated until a film of cesiated salt having a thickness of 1 angstrom to 10 microns is formed on a plurality of the fibers.
- 18. A method as recited in claim 17 wherein the fibers have tips, and only the tips are dipped in the molten cesiated salt solution.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of pending U.S. application Ser. No. 09/681,703 filed on May 23, 2001, and claims the benefit of the foregoing filing date.
STATEMENT OF GOVERNMENT INTEREST
[0002] The conditions under which this invention was made are such as to entitle the Government of the United States under paragraph 1(a) of Executive Order 10096, as represented by the Secretary of the Air Force, to the entire right, title and interest therein, including foreign rights.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09681703 |
May 2001 |
US |
Child |
10764806 |
Jan 2004 |
US |