US3259782A - Electron-emissive structure - Google Patents

Electron-emissive structure Download PDF

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Publication number
US3259782A
US3259782A US233081A US23308162A US3259782A US 3259782 A US3259782 A US 3259782A US 233081 A US233081 A US 233081A US 23308162 A US23308162 A US 23308162A US 3259782 A US3259782 A US 3259782A
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point
zirconium
electron
tungsten
present
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US233081A
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Arvind M Shroff
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Thales SA
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CSF Compagnie Generale de Telegraphie sans Fil SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H01J1/304—Field-emissive cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/021—Electron guns using a field emission, photo emission, or secondary emission electron source
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2918—Rod, strand, filament or fiber including free carbon or carbide or therewith [not as steel]
    • Y10T428/292—In coating or impregnation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
    • Y10T428/2958—Metal or metal compound in coating

Description

July 5, 1966 A. M. SHROFF 3,259,782
ELECTRON-EMISSIVE STRUCTURE Filed Oct. 25. 1962 INVENTOR HRvINo m. SHRoFF BY: 7 ml 7 HTTORNEY United States Patent 3,259,782 ELECTRON-EMISSIVE STRUCTURE Arvind M. Shroif, Paris, France, assignor to CSF-Compagnie Generale de Telegraphic Sans Fil, Paris, France Filed Oct. 25, 1962, Ser. No. 233,081 Claims priority, application France, Nov. 8, 1961, 878,265 6 Claims. '(Cl. 313-336) The present invention relates to a method for producing electron-emissive structures, and more particularly relates to a process for making point cathodes of the cold emission type as well as to the cold emission type cathode structures resulting from such method.
The most widely used form of a cold emission type electron emitter by extraction by means of a very intense electric field is the shape of a point having an extremely small radius of curvature. To obtain such a point, it is therefore necessary to have recourse to a pointing operation.
The known points are generally realized of tungsten, though other pure metals, such as platinum, molybdenum, or rhenium, have all been tested since all of these materials lend themselves with ease to the pointing operation, for example, by electro-chemical attack within an alkaline bath.
Nevertheless, it is of interest, and it has also already been proposed to realize these points of zirconium carbide, for this refractory material not only possesses a good conductivity but also possesses a working potential very much smaller than that of the afore-mentioned metals; consequently, the emission curve as a function of the applied field increases very rapidly, and, accordingly, a point made of zirconium carbide may form an electron emitter with very high current density.
However, the known manufacturing processes have proved to be incapable of producing points with sutficiently small radii of curvature. In these prior art processes, one either started with a block of zirconium carbide prefabricated by the usual methods, which did not lend itse f to the pointing operation, or one produced monocrystals of zirconium carbide which lend themselves well to the pointing operation by electrochemical attack within solutions, for example, of potassium fluoride within sulfuric acid, but these monocrystals are diflicult to prepare industrially.
The present invention essentially consists in a process for fabricating cold-emission-type electron emitters of zirconium carbide, which makes it possible to produce, in a simple manner, points of desired fineness, while avoiding at the same time the difliculties of the known methods and additionally permitting the simultaneous production of a large quantity of these points.
Accordingly, it is an object of the present invention to provide a process for producing point-like electron emitter structures of the type described hereinabove which effectively eliminates the shortcomings and drawbacks encountered with the prior art methods.
It is another object of the present invention to provide a method for producing cold emission electron emitter structures which may be manufactured with points of sufficiently small radius of curvature without great difficulties or expensive installations.
"Ice
Still a further object of the present invention resides in the provision of a method for producing point-like cold cathode structures of zirconium carbide which assure, in operation, a very high current density.
Another object of the present invention resides in the provision of a method for producing cathode structures of the type mentioned hereinabove that lends itself readily to mass-production techniques.
Still another object of the present invention resides in the provision of a cold cathode structure made of zirconium carbide having a very small radius of curvature which is obtained with the method of manufacture in accordance with the present invention.
According to the present invention, there is produced a point of zirconium carbide by starting with a point made of base metal, such as tungsten, that is pointed to the desired degree by any known method or process, thereupon evaporating on this base metal zirconium, and thereafter carburizing the zirconium by any known method, in the presence, for example of a heavy organic product, such as naphthalene or benzene.
According to another characteristic of the present invention, these operations take place simultaneously with a series of points.
The present invention is also applicable to cathodes made of the carbide of refractory metals other than zirconium, if it proves of advantage to utilize such carbide by reason of its relatively small working potential or other characteristics which may be found advantageous.
Thus, while I have described a preferred process in connection with zirconium carbide, it is understood that the present invention is not limited thereto, but is sus ceptible of many changes and modifications Within the spirit and scope thereof, and I therefore do not wish to be limited to the details described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.
The accompanying drawing shows a cold emission cathode comprising a plurality of metal points, each having a tungsten core 1 carrying a very thin coating 2 of zirconium carbide.
I claim:
1. A point-like cathode emitter, comprising a pointshaped tungsten support, and a thin layer of a zirconium carbide coating on said point-shaped support.
2. A point-like cathode emitter, comprising a pointshaped metallic support, and a thin layer of a zirconium carbide coating on said point-shaped support.
3. A process for making point cathodes having a high degree of field emission, comprising the steps of making a point-shaped support of tungsten, evaporating zirconium on said point-shaped tungsten support, and carburizing said zirconium in the presence of an organic atmosphere.
4. A process for mass-producing simultaneously a plurality of point cathodes having a high degree of field emission and utilizing a plurality of point-shaped tungsten supports, comprising the steps of simultaneously evaporating zirconium on said point-shaped supports, and thereafter simultaneously carburizing said zirconium in the presence of an organic atmosphere.
5. A process for making point cathodes having a high degree of field emission, comprising the steps of making a point-shaped support of a metal that can be easily pointed and selected from the group consisting of tungsten, platinum, molybdenum and rheniurn, evaporating zirconium on said point-shaped support, and carburizing said zirconium.
6. A process for making point cathodes having a high degree of field emission, comprising the steps of making a point-shaped support of a metal that can be easily pointed and selected from the group consisting of tungsten, platinum, molybdenum and rhenium, evaporating zirconium on said point-shaped support, and carburizing zirconium in the presence of an organic atmosphere.
References Cited by the Examiner UNITED STATES PATENTS JOHN W. HUCKERT, Primary Examiner.
said 10 JAMES KALLAM, Examiner.
R. F. POLISSACK, Assistant Examiner.

Claims (1)

1. A POINT-LIKE CATHODE EMITTER, COMPRISING AN POINTSHAPED TUNGSTEN SUPPORT, AND A THIN LAYER OF A ZIRCONIUM CARBIDE COATING ON SAID POINT-SHAPED SUPPORT.
US233081A 1961-11-08 1962-10-25 Electron-emissive structure Expired - Lifetime US3259782A (en)

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GB (1) GB949151A (en)
NL (1) NL285235A (en)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3374386A (en) * 1964-11-02 1968-03-19 Field Emission Corp Field emission cathode having tungsten miller indices 100 plane coated with zirconium, hafnium or magnesium on oxygen binder
US3413510A (en) * 1966-01-24 1968-11-26 Nasa Usa Electronic cathode having a brush-like structure and a relatively thick oxide emissive coating
US3484643A (en) * 1966-12-01 1969-12-16 Physics Int Co Boron carbide cathode for cold emission type cathode of the field emission type
US3500104A (en) * 1967-06-23 1970-03-10 Battelle Development Corp Electron emitter tips and method
US3678325A (en) * 1969-03-14 1972-07-18 Matsushita Electric Ind Co Ltd High-field emission cathodes and methods for preparing the cathodes
US3720856A (en) * 1970-07-29 1973-03-13 Westinghouse Electric Corp Binary material field emitter structure
US3723793A (en) * 1967-01-27 1973-03-27 Xerox Corp Coated corona generating electrode
US3814975A (en) * 1969-08-06 1974-06-04 Gen Electric Electron emission system
FR2301918A1 (en) * 1975-02-19 1976-09-17 Philips Nv CATHODIC TUBE EQUIPPED WITH A SOURCE EMITTING ELECTRONS UNDER THE ACTION OF AN ELECTRIC FIELD
WO1989004087A1 (en) * 1987-10-22 1989-05-05 Hughes Aircraft Company Microwave integrated distributed amplifier with field emission triodes
US5176557A (en) * 1987-02-06 1993-01-05 Canon Kabushiki Kaisha Electron emission element and method of manufacturing the same
US5201681A (en) * 1987-02-06 1993-04-13 Canon Kabushiki Kaisha Method of emitting electrons
US5202602A (en) * 1990-11-01 1993-04-13 The United States Of America As Represented By The Secretary Of The Navy Metal-glass composite field-emitting arrays
US5290610A (en) * 1992-02-13 1994-03-01 Motorola, Inc. Forming a diamond material layer on an electron emitter using hydrocarbon reactant gases ionized by emitted electrons
US5536193A (en) * 1991-11-07 1996-07-16 Microelectronics And Computer Technology Corporation Method of making wide band gap field emitter
US5543684A (en) * 1992-03-16 1996-08-06 Microelectronics And Computer Technology Corporation Flat panel display based on diamond thin films
WO1996038853A1 (en) * 1995-06-01 1996-12-05 Microelectronics And Computer Technology Corporation A field emission display device
US5600200A (en) * 1992-03-16 1997-02-04 Microelectronics And Computer Technology Corporation Wire-mesh cathode
US5601966A (en) * 1993-11-04 1997-02-11 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5612712A (en) * 1992-03-16 1997-03-18 Microelectronics And Computer Technology Corporation Diode structure flat panel display
US5628659A (en) * 1995-04-24 1997-05-13 Microelectronics And Computer Corporation Method of making a field emission electron source with random micro-tip structures
US5675216A (en) * 1992-03-16 1997-10-07 Microelectronics And Computer Technololgy Corp. Amorphic diamond film flat field emission cathode
US5679043A (en) * 1992-03-16 1997-10-21 Microelectronics And Computer Technology Corporation Method of making a field emitter
US6127773A (en) * 1992-03-16 2000-10-03 Si Diamond Technology, Inc. Amorphic diamond film flat field emission cathode
US6296740B1 (en) 1995-04-24 2001-10-02 Si Diamond Technology, Inc. Pretreatment process for a surface texturing process

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2156752A (en) * 1931-08-20 1939-05-02 Aeg Hot cathode discharge tube
US2159791A (en) * 1937-04-20 1939-05-23 Mallory & Co Inc P R Spark plug
US2282097A (en) * 1940-03-29 1942-05-05 Warren G Taylor Nonemitting electrode structure
US2786955A (en) * 1954-02-02 1957-03-26 Research Corp Transducer tube

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB230183A (en) * 1923-12-06 1925-03-06 Ruben Samuel Improvements in or relating to x-ray tubes

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2156752A (en) * 1931-08-20 1939-05-02 Aeg Hot cathode discharge tube
US2159791A (en) * 1937-04-20 1939-05-23 Mallory & Co Inc P R Spark plug
US2282097A (en) * 1940-03-29 1942-05-05 Warren G Taylor Nonemitting electrode structure
US2786955A (en) * 1954-02-02 1957-03-26 Research Corp Transducer tube

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3374386A (en) * 1964-11-02 1968-03-19 Field Emission Corp Field emission cathode having tungsten miller indices 100 plane coated with zirconium, hafnium or magnesium on oxygen binder
US3413510A (en) * 1966-01-24 1968-11-26 Nasa Usa Electronic cathode having a brush-like structure and a relatively thick oxide emissive coating
US3484643A (en) * 1966-12-01 1969-12-16 Physics Int Co Boron carbide cathode for cold emission type cathode of the field emission type
US3723793A (en) * 1967-01-27 1973-03-27 Xerox Corp Coated corona generating electrode
US3500104A (en) * 1967-06-23 1970-03-10 Battelle Development Corp Electron emitter tips and method
US3678325A (en) * 1969-03-14 1972-07-18 Matsushita Electric Ind Co Ltd High-field emission cathodes and methods for preparing the cathodes
US3814975A (en) * 1969-08-06 1974-06-04 Gen Electric Electron emission system
US3720856A (en) * 1970-07-29 1973-03-13 Westinghouse Electric Corp Binary material field emitter structure
FR2301918A1 (en) * 1975-02-19 1976-09-17 Philips Nv CATHODIC TUBE EQUIPPED WITH A SOURCE EMITTING ELECTRONS UNDER THE ACTION OF AN ELECTRIC FIELD
JPS51107756A (en) * 1975-02-19 1976-09-24 Philips Nv
JPS5616942B2 (en) * 1975-02-19 1981-04-20
US5176557A (en) * 1987-02-06 1993-01-05 Canon Kabushiki Kaisha Electron emission element and method of manufacturing the same
US5201681A (en) * 1987-02-06 1993-04-13 Canon Kabushiki Kaisha Method of emitting electrons
WO1989004087A1 (en) * 1987-10-22 1989-05-05 Hughes Aircraft Company Microwave integrated distributed amplifier with field emission triodes
US5202602A (en) * 1990-11-01 1993-04-13 The United States Of America As Represented By The Secretary Of The Navy Metal-glass composite field-emitting arrays
US5536193A (en) * 1991-11-07 1996-07-16 Microelectronics And Computer Technology Corporation Method of making wide band gap field emitter
US5861707A (en) * 1991-11-07 1999-01-19 Si Diamond Technology, Inc. Field emitter with wide band gap emission areas and method of using
US5290610A (en) * 1992-02-13 1994-03-01 Motorola, Inc. Forming a diamond material layer on an electron emitter using hydrocarbon reactant gases ionized by emitted electrons
US5686791A (en) * 1992-03-16 1997-11-11 Microelectronics And Computer Technology Corp. Amorphic diamond film flat field emission cathode
US5543684A (en) * 1992-03-16 1996-08-06 Microelectronics And Computer Technology Corporation Flat panel display based on diamond thin films
US5600200A (en) * 1992-03-16 1997-02-04 Microelectronics And Computer Technology Corporation Wire-mesh cathode
US6629869B1 (en) 1992-03-16 2003-10-07 Si Diamond Technology, Inc. Method of making flat panel displays having diamond thin film cathode
US5612712A (en) * 1992-03-16 1997-03-18 Microelectronics And Computer Technology Corporation Diode structure flat panel display
US6127773A (en) * 1992-03-16 2000-10-03 Si Diamond Technology, Inc. Amorphic diamond film flat field emission cathode
US5763997A (en) * 1992-03-16 1998-06-09 Si Diamond Technology, Inc. Field emission display device
US5703435A (en) * 1992-03-16 1997-12-30 Microelectronics & Computer Technology Corp. Diamond film flat field emission cathode
US5675216A (en) * 1992-03-16 1997-10-07 Microelectronics And Computer Technololgy Corp. Amorphic diamond film flat field emission cathode
US5679043A (en) * 1992-03-16 1997-10-21 Microelectronics And Computer Technology Corporation Method of making a field emitter
US5551903A (en) * 1992-03-16 1996-09-03 Microelectronics And Computer Technology Flat panel display based on diamond thin films
US5652083A (en) * 1993-11-04 1997-07-29 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5614353A (en) * 1993-11-04 1997-03-25 Si Diamond Technology, Inc. Methods for fabricating flat panel display systems and components
US5601966A (en) * 1993-11-04 1997-02-11 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5628659A (en) * 1995-04-24 1997-05-13 Microelectronics And Computer Corporation Method of making a field emission electron source with random micro-tip structures
US6296740B1 (en) 1995-04-24 2001-10-02 Si Diamond Technology, Inc. Pretreatment process for a surface texturing process
WO1996038853A1 (en) * 1995-06-01 1996-12-05 Microelectronics And Computer Technology Corporation A field emission display device

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DE1200442B (en) 1965-09-09
NL285235A (en)
GB949151A (en) 1964-02-12

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