EP1232511B1 - Oxide cathode - Google Patents

Oxide cathode Download PDF

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Publication number
EP1232511B1
EP1232511B1 EP01980367A EP01980367A EP1232511B1 EP 1232511 B1 EP1232511 B1 EP 1232511B1 EP 01980367 A EP01980367 A EP 01980367A EP 01980367 A EP01980367 A EP 01980367A EP 1232511 B1 EP1232511 B1 EP 1232511B1
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Prior art keywords
cathode
oxide
metal
particles
group
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EP01980367A
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German (de)
French (fr)
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EP1232511A1 (en
Inventor
Georg F. Gaertner
Detlef Raasch
Christopher J. Goodhand
Petrus A. M. Van Der Heide
Timothy J. Lee
Davis S Barrat
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Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
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Philips Intellectual Property and Standards GmbH
Koninklijke Philips Electronics NV
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/04—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
    • H01J1/13—Solid thermionic cathodes
    • H01J1/14—Solid thermionic cathodes characterised by the material

Definitions

  • the invention relates to an oxide anode comprising a cathode support having a cathode base of a first cathode metal and a cathode coating of an electron-emitting material containing a second cathode metal and at least one alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium.
  • the electron beam generation functional group includes an electron-emitting cathode which generates the electron current in the cathode ray tube and which is emitted by a control grid, e.g. a Wehnelt cylinder with a pinhole on the front side, is surrounded.
  • a control grid e.g. a Wehnelt cylinder with a pinhole on the front side
  • An electron-emitting cathode for a cathode ray tube is usually a point-shaped, heatable oxide cathode with an electron-emitting, oxide-containing cathode coating. When an oxide cathode is heated, electrons from the emitting coating are evaporated into the surrounding vacuum.
  • the amount of electrons that can be emitted from the cathode coating depends on the work function of the electron-emitting material.
  • Nickel which is typically used as a cathode base, has a relatively high work function by itself. Therefore, the metal of the cathode base is usually coated with a material whose main purpose is to improve the electron-emitting properties of the cathode base.
  • Characteristic of the Oxide oxide cathode electron-emitting coating materials are such that they contain an alkaline earth metal in the form of the alkaline earth metal oxide.
  • a correspondingly shaped sheet of nickel alloy is coated, for example, with the carbonates of the alkaline earth metals in a binder formulation.
  • the carbonates are converted to the oxides at temperatures of about 1000 ° C.
  • the activation process transforms the originally non-conducting ion lattice of the alkaline earth oxides into an electronic semiconductor by incorporating donor-type impurities into the crystal lattice of the oxides.
  • the impurities consist essentially of elemental alkaline earth metal, z.
  • the electron emission of the oxide cathodes is based on the impurity mechanism.
  • the purpose of the activation process is to provide a sufficient amount of excess elemental alkaline earth metal that allows the oxides in the electron-emitting coating to deliver the maximum emission current at a prescribed heat output.
  • An essential contribution to the activation process is the reduction of barium oxide to elemental barium by alloy components ("activators") of the nickel from the cathode base.
  • the cathode coating constantly loses alkaline earth metal during the life of the cathode. Partly the cathode material evaporates slowly in total, partly it is sputtered off by the ion current in the cathode ray tube.
  • the elemental alkaline earth metal is replenished again and again.
  • the subsequent delivery of elemental alkaline earth metal by reduction of the alkaline earth metal oxide at the cathode metal or activator metal comes to a standstill, if formed between the cathode base and the emitting oxide with time a thin, but high-impedance interface (interface) of alkaline earth silicate or alkaline earth aluminate.
  • an oxide cathode with improved donor density and extended life comprising a nickel alloy cup filled with a nickel alloy wire ball and an alkaline earth carbonate mixture.
  • US 4797593 discloses an oxide cathode having an improved electron emission characteristic comprising a base containing nickel as the principal element and a base layer of an electron-emitting substance, which layer includes not only alkali metal oxides as the principal component of at least barium but also rare -Erd metal oxides containing by weight between 0.1 and 20 wt .-% or rare earth metals having a weight fraction between 0.05 and 17 wt .-%.
  • the electron-emitting layer further comprises a powder of at least one of nickel and cobalt in a weight proportion of 10% by weight or less. Nickel and / or cobalt powders serve to provide better conductivity for the electron-emitting layer and to improve the adhesion properties of this layer. Nonetheless, the powder does not affect or enhance the distribution of the elemental alkali metal oxide.
  • an oxide cathode comprising a cathode support having a cathode base made of a first cathode metal with a cover layer consisting of ultrafine metal particles containing nickel, and a cathode coating of an electron-emitting material comprising a particle-particle composite oxide particles and metal particles, the oxide particles comprising an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium and an alkaline earth oxide selected from of the group of oxides of calcium, strontium and barium, and the metal particles comprise a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt.
  • a cathode ray tube having such an oxide cathode has a uniform beam current over a long period of time because the homogeneous distribution of the reducing cathode metal and the activator metal in the material of the electron-emitting cathode coating, the growth of high-resistance intermediate layers is distributed locally and reduced overall. It can be supplied longer elementary barium.
  • the covering layer which consists of ultrafine metal particles containing nickel, is particularly advantageous. It forms a dissolved border between cathode base and cathode coating. As a result, the formation of a high-impedance deactivating separating layer between the cathode base and the cathode coating is discontinuous and the resistance of the high-resistance separating layer is reduced. Local activator replenishment and activator diffusion is encouraged.
  • Continuous barium tracking avoids electron emission depletion, as known from conventional oxide cathodes. Significantly higher beam current densities can be realized without jeopardizing the cathode lifetime. This can also be exploited to pull the necessary electron beam currents from smaller cathode areas.
  • the spot size of the cathode spot is critical to the quality of beam focusing on the screen. The image sharpness over the entire screen is increased. Moreover, as the cathodes age very slowly, image brightness and image sharpness can be kept stable at a high level throughout the life of the tube.
  • the first cathode metal is preferably a metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt.
  • the first cathode metal is an alloy of a metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo , Cr, Ti, Hf, Zr, Al.
  • the cover layer additionally contains an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al. This reduces the sensitivity to "poisoning" by residual gases in the cathode tube vacuum. It is particularly preferred if the metal particles contain a slow activator selected from the group Al, Mo, Ti and Si. The slow activators are preferably added in an amount of 1 to 4 wt .-%.
  • the metal particles in the electron-emitting material may also be preferred for the metal particles in the electron-emitting material to be an alloy of a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  • a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt
  • an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  • the oxide particles may be oxide particles of an alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium, with an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, Samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium
  • the oxide particles contain oxide particles of an alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium, which is doped with one of the oxide of yttrium.
  • Yttrium oxide surprisingly accelerates the sintering of the oxides in the production.
  • the oxide particles contain oxide particles of an oxide selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and Oxide particles of an alkaline earth oxide, selected from the group of the oxides of calcium, strontium and barium.
  • the electron-emitting material may contain 1 to 5 wt% of metal particles.
  • the electron-emitting material contains 2.5 wt .-% nickel particles.
  • the metal particles have an ellipsoidal or spherical shape. This makes the diffusion of the activator metals more controlled and the barium emission locally and temporally more uniform.
  • the mean particle diameter of the metal particles is preferably 0.2 to 5.0 ⁇ m.
  • the metal particles are embedded in the particle-particle composite oriented, in particular that the metal particles in the particle-particle composite are embedded vertically to the cathode base surface.
  • the metal particles are embedded in the particle-particle composite with a concentration gradient.
  • the invention also relates to an oxide cathode comprising a cathode support having a cathode base of a first cathode metal with a cover layer consisting of ultrafine metal particles containing nickel, and a cathode coating of an electron-emitting material comprising a particle-particle composite of oxide particles and Contains metal particles, wherein the oxide particles selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium and an alkaline earth oxide selected from the Group of oxides of calcium, strontium and barium, and the metal particles containing a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt comprises.
  • Fig. 1 shows a schematic cross section through an embodiment of the oxide cathode according to the invention.
  • a cathode ray tube is provided with an electron gun, usually including an array with one or more oxide cathodes.
  • An oxide cathode according to the invention comprises a cathode support having a cathode base and a cover layer consisting of ultrafine metal particles containing nickel and a cathode coating.
  • the cathode support contains the heater and the base with the topcoat.
  • the structures and materials known from the prior art can be used as the cathode support.
  • the oxide cathode consists of a cathode support, i. a cylindrical tube 3, in which the heating wire 4 is inserted, from a cap 2, which forms the cathode base, with the cover layer 7 and from a cathode coating 1, which represents the actual cathode body.
  • the material of the cathode base is preferably a metal selected from the group Ni, Co, Ir, Re, Pd, Rh and Pt.
  • a nickel alloy is used.
  • the nickel alloys for the base of the oxide cathodes according to the invention may consist of nickel with an alloying component of a reducing activator element selected from the group of magnesium, manganese, iron, silicon, tungsten, molybdenum, chromium, titanium, hafnium, zirconium and aluminum. Since the cathode coating also contains activator elements, the amount of activator elements in the cathode base material can be kept low. An alloying amount of 0.05 to 0.8% of activator metal in the cathode base material is preferred.
  • the cathode base is coated with a topcoat consisting of ultrafine metal particles containing nickel.
  • the particle size of the ultrafine particles is less than 100 nm.
  • the ultrafine particles preferably contain an activator selected from the group consisting of Mg, Al, Mo, Ti, Si, Cr, Zr, Mg. It is particularly preferred if the metal particles comprise a slow activator Group Al, Mo, Ti and Si contains.
  • the slow activators are preferably added in an amount of 1 to 4 wt .-%.
  • the cathode coating contains an electron-emitting material that consists of a particle-particle composite.
  • the main component of the particle-particle composite in the electron-emitting material are oxide particles 6 comprising an oxide selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, Thulium, ytterbium and lutetium; and an alkaline earth oxide selected from the group of oxides of calcium, strontium and barium.
  • the oxide particles may include oxide particles having alkaline earth metal oxides doped with the oxides of scandium, yttrium and lanthanides such as cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
  • the oxide particles contain oxide particles with oxides of the alkaline earth metal, and oxide particles with the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
  • Barium oxide, together with calcium oxide or / and strontium oxide is preferred as the alkaline earth oxide.
  • the alkaline earth oxides are used as a physical mixture of alkaline earth oxides or as binary or ternary mixed crystals of the alkaline earth metal oxides. Preferred is a ternary alkaline earth mixed crystal oxide of barium oxide, strontium oxide and calcium oxide or a binary mixture of barium oxide and calcium oxide.
  • the alkaline earth oxide may be doped with an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, e.g. B. in an amount of 10 to a maximum of 1000 ppm included.
  • the ions of scandium, yttrium and lanthanides occupy lattice sites or interstitials in the crystal lattice of alkaline earth metal oxides.
  • Yttrium is preferably used as doping.
  • the doped oxides are obtained by coprecipitation.
  • oxide particles of the alkaline earth oxides and oxide particles of the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium can also be prepared separately and used as a physical mixture become.
  • the particle-particle composite of the electron-emitting material contains, as a second component, metal particles 5 containing the second cathode metal.
  • the material for the second component is an alloy of a second one Cathode metal selected from the group Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  • metal particles having a spherical or ellipsoidal grain shape may be preferably used.
  • the mean grain diameter is preferably 0.2 to 5 microns. It is also possible to use needle-shaped metal particles having a maximum grain diameter of 10 to 15 ⁇ m. Such acicular particles may be aligned vertically to the cathode base by suitable deposition techniques.
  • the slowly diffusing activator metals such as Mo and W in a concentration of 2 to 10 wt .-% in the alloy are particularly suitable.
  • the faster diffusing activator metals such as Zr and Mg are suitable.
  • the ultrafine particles containing nickel or nickel and another cathode metal can be prepared from the respective targets by a laser ablation method.
  • These targets contain cathode nickel, which can be alloyed with activators such as Mg.Al, Ti, Zr, Si, Cr, Zr, and Mg.
  • the ultrafine particles for the topcoat may be prepared separately and applied to the cathode base by a conventional coating process. It is also possible to deposit the ultrafine particles for the cover layer directly by laser ablation on the cathode base. It is also possible to use wet-chemical or sol-gel preparation methods to prepare the ultrafine particles.
  • the carbonates of the alkaline earth metals calcium, strontium and barium are ground together and mixed.
  • the weight ratio of calcium carbonate: strontium carbonate: barium carbonate: zirconium is equal to 25.2: 31.5: 40.3: 3.or1: 1.25: 6 or 1:12:22 or 1: 1.5: 2.5 or 1: 4: 6 ,
  • One or more oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium are added to the carbonates.
  • Y 2 O 3 is added in an amount of 130 ppm.
  • Carbonates, oxides and metal particles are mixed into the raw material.
  • the raw material can still be added to a binder preparation.
  • the binder preparation may contain, as solvent, water, ethanol, ethyl nitrate, ethyl acetate, or diethyl acetate.
  • the raw material for the cathode coating is then applied to the cathode base by brushing, dipping, cataphoretic deposition or spraying.
  • the thickness of the cathode coating is preferably 30 to 80 ⁇ m.
  • the coated oxide cathodes are installed in the cathode ray tube. During the evacuation of the cathode ray tube, the cathodes are formed. For this purpose, they are heated to a temperature of 1000 ° C to 1200 ° C. At this temperature, the alkaline earth carbonates are converted to the alkaline earth oxides to release CO and CO 2 and then form a porous sintered body. After this "burning off" of the cathodes is the activation, which has the purpose to provide excess, embedded in the oxides, elemental alkaline earth metal. The excess alkaline earth metal is formed by reduction of alkaline earth metal oxide. During the actual reduction activation, the alkaline earth oxide is reduced by the liberated CO or activator metal. In addition, there is a current activation, which generates the formation of the required free alkaline earth metal by electrolytic processes at high temperatures.
  • the finished-formed, electron-emitting material may preferably contain 1 to 5 wt .-% metal particles.
  • a cathode tube cathode has a cap-shaped cathode base made of an alloy of nickel with 0.12 wt% Mg, 0.06 wt% Al, and 2.0 wt% W assures on.
  • the cathode base is located at the top of a cylindrical cathode support (sleeve) in which the heater is mounted.
  • the cathode base is placed in the ablation chamber of a laser ablation unit.
  • An excimer laser beam is directed at a pressure of a few mbars onto a rotating cylindrical cathode-nickel target containing an appropriate amount of activators and ablates it.
  • a plasma torch with ablated ultrafine particles forms over the target.
  • These ablated ultrafine particles are transported to the cathode base by means of a carrier gas flow of Ar / H 2 and deposited there.
  • the carrier gas of Ar / H 2 prevents oxidation of the particles during transport.
  • Other inert gases may also be suitable for this purpose.
  • the laser ablation is started at low pressures by 10 -2 mbar and low carrier gas pressure, whereby initially a fine-grained compact layer of nickel particles is formed. Subsequently, the gas pressure and the carrier gas flow are increased to achieve deposition of ultrafine particles. This allows a continuous transition from compact layers to ultra-fine particle layers.
  • the cathode has a cathode coating on top of the cathode base.
  • the cathode base is first cleaned. Then, 2.0 wt% metal particles and 98 wt% powder of a starting compound for the oxide particles containing 130 ppm of yttria are suspended in a solution of ethanol, butyl acetate and nitrocellulose.
  • the metal particles consist of an alloy of nickel with 0.02 wt .-% Al, 3.0 wt .-% W and 6.0 wt .-% Mo.
  • the metal particles have a needle-like grain shape with a mean needle length of 3 ⁇ 2 microns.
  • the powder with the starting compounds for the oxide particles consists of barium strontium carbonate with 130 ppm yttrium oxide. This suspension is sprayed onto the cathode base.
  • the layer is formed at a temperature of 650 to 1100 ° C to effect alloying and diffusion between the metal base of the metal base and the metal particles.
  • the cathode thus formed has a direct current capability of 4 A / cm 2 with a lifetime of 20,000 h and a tube internal pressure of 2 * 10 -9 bar.

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Abstract

The invention relates to a cathode ray tube equipped with at least one oxide cathode comprising a cathode carrier having a cathode base of a first cathode metal and having a covering layer of ultrafine metal particles that contain nickel. The oxide cathode also comprises a cathode coating of an electron-emitting material containing a particle-particle composite of oxide particles and metal particles. The oxide particles comprise an oxide selected among the oxides of scandium, yttrium and the lanthanoids cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and an alkaline earth oxide selected among the group consisting of the oxides of calcium, strontium and barium, and the metal particles contain a second cathode material selected from the group consisting of Ni, Co, Ir, Pd, Rh and Pt. The invention also relates to an oxide cathode.

Description

Die Erfindung betrifft eine Oxidkanode, die einen Kathodenträger mit einer Kathodenbasis aus einem ersten Kathodenmetall und eine Kathodenbeschichtung aus einem elektronenemittierenden Material, das ein zweites Kathodenmetall und mindestens ein Erdalkalioxid, ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Barium, enthält, umfasst.The invention relates to an oxide anode comprising a cathode support having a cathode base of a first cathode metal and a cathode coating of an electron-emitting material containing a second cathode metal and at least one alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium.

Eine Kathodenstrahlröhre besteht aus vier Funktionsgruppen:

  • Elektronenstrahlerzeugung in der Elektronenkanone,
  • Strahlfokussierung durch elektrische oder magnetische Linsen
  • Strahlablenkung zur Rastererzeugung und
  • Leuchtschirm oder Bildschirm.
A cathode ray tube consists of four functional groups:
  • Electron beam generation in the electron gun,
  • Beam focusing by electric or magnetic lenses
  • Beam deflection for grid generation and
  • Luminescent screen or screen.

Zu der Funktionsgruppe der Elektronenstrahlerzeugung gehört eine elektronenemittierende Kathode, die den Elektronenstrom in der Kathodenstrahlröhre erzeugt und die von einem Steuergitter, z.B. einem Wehnelt-Zylinder mit einer Lochblende auf der Stirnseite, umgeben ist.The electron beam generation functional group includes an electron-emitting cathode which generates the electron current in the cathode ray tube and which is emitted by a control grid, e.g. a Wehnelt cylinder with a pinhole on the front side, is surrounded.

Eine elektronenemittierende Kathode für eine Kathodenstrahlröhre ist üblicherweise eine punktförmige, heizbare Oxidkathode mit einer elektronenemittierenden, oxidhaltigen Kathodenbeschichtung. Wird eine Oxidkathode aufgeheizt, werden Elektronen aus der emittierenden Beschichtung in das umgebende Vakuum ausgedampft.An electron-emitting cathode for a cathode ray tube is usually a point-shaped, heatable oxide cathode with an electron-emitting, oxide-containing cathode coating. When an oxide cathode is heated, electrons from the emitting coating are evaporated into the surrounding vacuum.

Die Menge der Elektronen, die von der Kathodenbeschichtung emittiert werden können, hängt von der Austrittsarbeit (work function) des elektronenemittierenden Materials ab. Nickel, das in der Regel als Kathodenbasis verwendet wird, hat selbst eine relativ hohe Austrittsarbeit. Deshalb wird das Metall der Kathodenbasis üblicherweise noch mit einem Material beschichtet, dessen Hauptaufgabe es ist, die elektronenemittierenden Eigenschaften der Kathodenbasis zu verbessern. Charakteristisch für die elektronenemittierenden Beschichtungsmaterialien von Oxidkathoden ist es, dass sie ein Erdalkalimetall in der Form des Erdalkalimetalloxids enthalten.The amount of electrons that can be emitted from the cathode coating depends on the work function of the electron-emitting material. Nickel, which is typically used as a cathode base, has a relatively high work function by itself. Therefore, the metal of the cathode base is usually coated with a material whose main purpose is to improve the electron-emitting properties of the cathode base. Characteristic of the Oxide oxide cathode electron-emitting coating materials are such that they contain an alkaline earth metal in the form of the alkaline earth metal oxide.

Um eine Oxidkathode herzustellen, wird ein entsprechend geformtes Blech aus einer Nickellegierung beispielsweise mit den Carbonaten der Erdalkalimetalle in einer Bindemittelzubereitung beschichtet. Während des Auspumpens und Ausheizens der Kathodenstrahlröhre werden die Carbonate bei Temperaturen von etwa 1000°C in die Oxide umgewandelt. Nach diesem Abbrennen der Kathode liefert sie bereits einen merklichen Emissionsstrom, der allerdings noch nicht stabil ist. Es folgt noch ein Aktivierungsprozess. Durch den Aktivierungsprozess wird das ursprünglich nichtleitende Ionengitter der Erdalkalioxide in einen elektronischen Halbleiter verwandelt, indem Störstellen vom Donator-Typ in das Kristallgitter der Oxide eingebaut werden. Die Störstellen bestehen im wesentlichen aus elementarem Erdalkalimetall, z. B. Calcium, Strontium oder Barium. Die Elektronenemission der Oxidkathoden basiert auf dem Störstellenmechanismus. Der Aktivierungsprozess hat den Zweck, eine genügende Menge von überschüssigem, elementarem Erdalkalimetall zu schaffen, durch das die Oxide in der elektronenemittierenden Beschichtung bei einer vorgeschriebenen Heizleistung den maximalen Emissionsstrom liefern können. Einen wesentlichen Beitrag zu dem Aktivierungsprozess leistet die Reduktion des Bariumoxids zu elementarem Barium durch Legierungsbestandteile ("Aktivatoren") des Nickels aus der Kathodenbasis.In order to produce an oxide cathode, a correspondingly shaped sheet of nickel alloy is coated, for example, with the carbonates of the alkaline earth metals in a binder formulation. During the pumping and bakeout of the cathode ray tube, the carbonates are converted to the oxides at temperatures of about 1000 ° C. After this burning of the cathode, it already provides a significant emission current, which is not yet stable. There is still an activation process. The activation process transforms the originally non-conducting ion lattice of the alkaline earth oxides into an electronic semiconductor by incorporating donor-type impurities into the crystal lattice of the oxides. The impurities consist essentially of elemental alkaline earth metal, z. As calcium, strontium or barium. The electron emission of the oxide cathodes is based on the impurity mechanism. The purpose of the activation process is to provide a sufficient amount of excess elemental alkaline earth metal that allows the oxides in the electron-emitting coating to deliver the maximum emission current at a prescribed heat output. An essential contribution to the activation process is the reduction of barium oxide to elemental barium by alloy components ("activators") of the nickel from the cathode base.

Wichtig für die Funktion einer Oxidkathode und deren Lebensdauer ist es, dass immer wieder erneut elementares Erdalkalimetall zur Verfügung steht. Die Kathodenbeschichtung verliert nämlich während der Lebensdauer der Kathode ständig Erdalkalimetall. Teils verdampft langsam das Kathodenmaterial insgesamt, teils wird es durch den Ionenstrom in der Kathodenstrahlröhre abgesputtert.Important for the function of an oxide cathode and its lifetime is that again and again elemental alkaline earth metal is available. Namely, the cathode coating constantly loses alkaline earth metal during the life of the cathode. Partly the cathode material evaporates slowly in total, partly it is sputtered off by the ion current in the cathode ray tube.

Allerdings wird zunächst das elementare Erdalkalimetall immer wieder nachgeliefert. Die Nachlieferung von elementarem Erdalkalimetall durch Reduktion des Erdalkalioxids am Kathodenmetall bzw. Aktivatormetall kommt jedoch zum Stillstand, wenn sich zwischen der Kathodenbasis und dem emittierenden Oxid mit der Zeit eine dünne, aber hochohmige Trennschicht (interface) aus Erdalkalisilikat oder Erdalkalialuminat bildet. Von Einfluss auf die Lebensdauer ist es weiterhin, dass sich der Vorrat an Aktivatormetall in der Nickellegierung der Kathodenbasis mit der Zeit erschöpft.However, initially the elemental alkaline earth metal is replenished again and again. However, the subsequent delivery of elemental alkaline earth metal by reduction of the alkaline earth metal oxide at the cathode metal or activator metal comes to a standstill, if formed between the cathode base and the emitting oxide with time a thin, but high-impedance interface (interface) of alkaline earth silicate or alkaline earth aluminate. In addition, it is an influence on the lifetime that the supply of activator metal in the nickel alloy of the cathode base is depleted over time.

Aus der JP 11204019 A ist eine Oxidkathode mit verbesserter Donordichte und verlängerter Lebensdauer bekannt, die einen Napf aus einer Nickellegierung umfasst, der mit einem Drahtknäuel aus einer Nickellegierung und mit einem Erdalkalicarbonatgemisch gefüllt ist.From the JP 11204019 A For example, an oxide cathode with improved donor density and extended life is known comprising a nickel alloy cup filled with a nickel alloy wire ball and an alkaline earth carbonate mixture.

US 4797593 offenbart eine Oxidkathode mit einer verbesserten Elektronenemissions-Charakteristik umfassend eine Basis, die Nickel als das hauptsächliche Element enthält, und eine auf die Basis aufgebrachte Schicht aus einer elektronenemittierenden Substanz, wobei die Schicht nicht nur Alkalimetalloxide als die hauptsächliche Komponente mit zumindest Barium, sondern auch Selten-Erd-Metalloxide mit einem Gewichtsanteil zwischen 0,1 und 20 Gew.-% oder Selten-Erd-Metalle mit einem Gewichtsanteil zwischen 0,05 und 17 Gew.-% enthält. Die elektronenemittierende Schicht umfasst weiterhin ein Pulver aus zumindest einem der Materialien Nickel und Kobalt mit einem Gewichtsanteil von 10 Gew.-% oder weniger. Nickel und/oder Kobalt-Pulver dienen zur Bereitstellung einer besseren Leitfähigkeit für die elelctronenemittierende Schicht und zur Verbesserung der Adhäsionseigenschaften dieser Schicht. Nichtsdestotrotz beeinflusst oder verstärkt das Pulver nicht die Verteilung des elementaren Alkali-Metalloxids. US 4797593 discloses an oxide cathode having an improved electron emission characteristic comprising a base containing nickel as the principal element and a base layer of an electron-emitting substance, which layer includes not only alkali metal oxides as the principal component of at least barium but also rare -Erd metal oxides containing by weight between 0.1 and 20 wt .-% or rare earth metals having a weight fraction between 0.05 and 17 wt .-%. The electron-emitting layer further comprises a powder of at least one of nickel and cobalt in a weight proportion of 10% by weight or less. Nickel and / or cobalt powders serve to provide better conductivity for the electron-emitting layer and to improve the adhesion properties of this layer. Nonetheless, the powder does not affect or enhance the distribution of the elemental alkali metal oxide.

Es ist eine Aufgabe der Erfindung, eine Kathodenstrahlröhre zur Verfügung zu stellen, deren Strahlstrom gleichmäßig ist, über lange Zeit konstant bleibt und die reproduzierbar herstellbar istIt is an object of the invention to provide a cathode ray tube whose beam current is uniform, remains constant over a long time and which can be produced reproducibly

Erfindungsgemäß wird die Aufgabe gelöst durch eine Oxidkathode, die einen Kathodenträger mit einer Kathodenbasis aus einem ersten Kathodenmetall mit einer Deckschicht, die aus ultrafeinen Metallpartikel, die Nickel enthalten, besteht und eine Kathodenbeschichtung aus einem elektronenemittierenden Material, das einen Partikel-Partikel-Verbundwerkstoff aus Oxidpartikeln und Metallpartikeln enthält, wobei die Oxidpartikel ein Oxid ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium und ein Erdalkalioxid ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums, und die Metallpartikel ein zweites Kathodenmetall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt enthalten, umfasst.According to the invention, the object is achieved by an oxide cathode comprising a cathode support having a cathode base made of a first cathode metal with a cover layer consisting of ultrafine metal particles containing nickel, and a cathode coating of an electron-emitting material comprising a particle-particle composite oxide particles and metal particles, the oxide particles comprising an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium and an alkaline earth oxide selected from of the group of oxides of calcium, strontium and barium, and the metal particles comprise a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt.

Eine Kathodenstrahlröhre mit einer derartigen Oxidkathode hat über einen langen Zeitraum hin einen gleichmäßigen Strahlstrom, weil durch die homogene Verteilung des reduzierend wirkenden Kathodenmetalls und des Aktivatormetalls in dem Material der elektronenemittierenden Kathodenbeschichtung das Wachstum von hochohmigen Zwischenschichten lokal verteilt und insgesamt reduziert ist. Es kann länger elementares Barium nachgeliefert werden. Besonders vorteilhaft wirkt dabei die Deckschicht, die aus ultrafeinen Metallpartiken, die Nickel enthalten, besteht. Sie bildet eine aufgelöste Grenze zwischen Kathodenbasis und Kathodenbeschichtung. Dadurch wird die Bildung einer hochohmigen desaktivierenden Trennschicht zwischen Kathodenbasis und Kathodenbeschichtung diskontinuierlich und der Widerstand der hochohmigen Trennschicht reduziert. Die lokale Aktivatornachlieferung und die Aktivatordiffusion wird gefördert.A cathode ray tube having such an oxide cathode has a uniform beam current over a long period of time because the homogeneous distribution of the reducing cathode metal and the activator metal in the material of the electron-emitting cathode coating, the growth of high-resistance intermediate layers is distributed locally and reduced overall. It can be supplied longer elementary barium. The covering layer, which consists of ultrafine metal particles containing nickel, is particularly advantageous. It forms a dissolved border between cathode base and cathode coating. As a result, the formation of a high-impedance deactivating separating layer between the cathode base and the cathode coating is discontinuous and the resistance of the high-resistance separating layer is reduced. Local activator replenishment and activator diffusion is encouraged.

Durch die kontinuierliche Barium-Nachführung wird eine Erschöpfung der Elektronenemission, wie man die von herkömmlichen Oxidkathoden kennt, vermieden. Es können ohne Gefährdung der Kathodenlebensdauer wesentlich höhere Strahlstromdichten realisiert werden. Das kann auch ausgenutzt werden, um die notwendigen Elektronenstrahlströme aus kleineren Kathodenbereichen zu ziehen. Die Spotgröße des Kathodenflecks ist entscheidend für die Güte der Strahlfokussierung auf dem Bildschirm. Die Bildschärfe über den gesamten Schirm wird erhöht. Da die Kathoden zudem nur sehr langsam altern, können Bildhelligkeit und Bildschärfe auf hohem Niveau über die gesamte Lebensdauer der Röhre stabil gehalten werden.Continuous barium tracking avoids electron emission depletion, as known from conventional oxide cathodes. Significantly higher beam current densities can be realized without jeopardizing the cathode lifetime. This can also be exploited to pull the necessary electron beam currents from smaller cathode areas. The spot size of the cathode spot is critical to the quality of beam focusing on the screen. The image sharpness over the entire screen is increased. Moreover, as the cathodes age very slowly, image brightness and image sharpness can be kept stable at a high level throughout the life of the tube.

Als erstes Kathodenmetall wird bevorzugt ein Metall aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt gewählt.The first cathode metal is preferably a metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt.

Besonders bevorzugt ist es, dass das erste Kathodenmetall eine Legierung aus einem Metall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt mit einem Aktivatormetall, ausgewählt aus der Gruppe Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al enthält.It is particularly preferred that the first cathode metal is an alloy of a metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo , Cr, Ti, Hf, Zr, Al.

Nach einer bevorzugten Ausführungsform enthält die Deckschicht zusätzlich ein Aktivatormetall, ausgewählt aus der Gruppe Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al. Dadurch wird die Sensitivität gegen eine "Vergiftung" durch Restgase im Kathodenröhrenvakuum reduziert.
Besonders bevorzugt ist es, wenn die Metallpartikel einen langsamen Aktivator ausgewählt der Gruppe Al, Mo, Ti und Si enthält. Die langsamen Aktivatoren werden bevorzugt in einer Menge von 1 bis 4 Gew.-% zugesetzt.According to a preferred embodiment, the cover layer additionally contains an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al. This reduces the sensitivity to "poisoning" by residual gases in the cathode tube vacuum.
It is particularly preferred if the metal particles contain a slow activator selected from the group Al, Mo, Ti and Si. The slow activators are preferably added in an amount of 1 to 4 wt .-%.

Es kann auch bevorzugt sein, dass die Metallpartikel in dem elektronenemittierenden Material eine Legierung aus einem zweiten Kathodenmetall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt mit einem Aktivatormetall, ausgewählt aus der Gruppe Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al enthalten.
Die Oxidpartikel können Oxidpartikel eines Erdalkalioxids ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums, das mit einem Oxid ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium dotiert ist, enthaltenIt may also be preferred for the metal particles in the electron-emitting material to be an alloy of a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
The oxide particles may be oxide particles of an alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium, with an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, Samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium

Nach einer besonders bevorzugten Ausführungsform enthalten die Oxidpartikel Oxidpartikel eines Erdalkalioxids ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums, das mit einem der Oxid des Yttriums dotiert ist, enthalten. Yttriumoxid beschleunigt überraschenderweise die Sinterung der Oxide bei der Herstellung.According to a particularly preferred embodiment, the oxide particles contain oxide particles of an alkaline earth oxide selected from the group of the oxides of calcium, strontium and barium, which is doped with one of the oxide of yttrium. Yttrium oxide surprisingly accelerates the sintering of the oxides in the production.

Nach einer anderen Ausführungsform der Erfindung enthalten die Oxidpartikel Oxidpartikel eines Oxids ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium, und Oxidpartikel eines Erdalkalioxids, ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums.According to another embodiment of the invention, the oxide particles contain oxide particles of an oxide selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and Oxide particles of an alkaline earth oxide, selected from the group of the oxides of calcium, strontium and barium.

Das elektronenemittierende Material kann 1 bis 5 Gew.-%Metallpartikel enthalten.The electron-emitting material may contain 1 to 5 wt% of metal particles.

Besonders bevorzugt ist es, dass das elektronenemittierende Material 2,5 Gew.-% Nickelpartikel enthält.It is particularly preferred that the electron-emitting material contains 2.5 wt .-% nickel particles.

Besonders vorteilhafte Wirkungen werden durch die Erfindung gegenüber dem Stand der Technik erreicht, wenn die Metallpartikel eine ellipsoidale oder kugelige Form haben. Dadurch wird die Diffusion der Aktivatormetalle kontrollierter und die Barium-Emission örtlich und zeitlich uniformer. Man erhält Oxidkathoden mit höherer Gleichstrombelastbarkeit und Lebensdauer.
Wenn die Metallpartikel eine nadelige Form haben, kann das dazu beitragen, die Diffusion der Aktivatormetalle während des gesamten Lebensdauer der Oxidkathode gleichmäßig zu halten.Particularly advantageous effects are achieved by the invention over the prior art, when the metal particles have an ellipsoidal or spherical shape. This makes the diffusion of the activator metals more controlled and the barium emission locally and temporally more uniform. One obtains oxide cathodes with higher direct current capacity and lifetime.
If the metal particles have a needle-like shape, this can help to keep the diffusion of the activator metals uniform throughout the lifetime of the oxide cathode.

Der mittlere Partikeldurchmesser der Metallpartikel beträgt vorzugsweise 0.2 bis 5.0 µm.The mean particle diameter of the metal particles is preferably 0.2 to 5.0 μm.

Es kann auch bevorzugt sein, dass die Metallpartikel in dem Partikel-Partikel-Verbundwerkstoff orientiert eingebettet sind, insbesondere, dass die Metallpartikel in dem Partikel-Partikel-Verbundwerkstoff vertikal zur Kathodenbasis-Oberfläche eingebettet sind.It may also be preferred that the metal particles are embedded in the particle-particle composite oriented, in particular that the metal particles in the particle-particle composite are embedded vertically to the cathode base surface.

Es ist auch möglich, dass die Metallpartikel in dem Partikel-Partikel-Verbundwerkstoff mit einem Konzentrationsgradienten einbettet sind.It is also possible that the metal particles are embedded in the particle-particle composite with a concentration gradient.

Die Erfindung betrifft auch eine Oxidkathode, die einen Kathodenträger mit einer Kathodenbasis aus einem ersten Kathodenmetall mit einer Deckschicht, die aus ultrafeinen Metallpartikel, die Nickel enthalten, besteht, und eine Kathodenbeschichtung aus einem elektronenemittierenden Material, das einen Partikel-Partikel-Verbundwerkstoff aus Oxidpartikeln und Metallpartikeln enthält, wobei die Oxidpartikel ein Oxid ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium und ein Erdalkalioxid ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums, und die Metallpartikel ein zweites Kathodenmetall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt enthalten, umfasst.The invention also relates to an oxide cathode comprising a cathode support having a cathode base of a first cathode metal with a cover layer consisting of ultrafine metal particles containing nickel, and a cathode coating of an electron-emitting material comprising a particle-particle composite of oxide particles and Contains metal particles, wherein the oxide particles selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium and an alkaline earth oxide selected from the Group of oxides of calcium, strontium and barium, and the metal particles containing a second cathode metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt comprises.

Nachfolgend wird die Erfindung anhand von einer Figur und einem Ausführungsbeispiel weiter erläutert.The invention will be further explained with reference to a figure and an embodiment.

Fig. 1 zeigt einen schematischen Querschnitt durch eine Ausführungsform der Oxidkathode nach der Erfindung.Fig. 1 shows a schematic cross section through an embodiment of the oxide cathode according to the invention.

Eine Kathodenstrahlröhre ist mit einem Elektronenstrahlerzeugungssystem ausgestattet, das üblicherweise eine Anordnung mit einer oder mehreren Oxidkathoden enthält.A cathode ray tube is provided with an electron gun, usually including an array with one or more oxide cathodes.

Eine Oxidkathode nach der Erfindung umfasst einen Kathodenträger mit einer Kathodenbasis und einer Deckschicht, die aus ultrafeinen Metallpartikel, die Nickel enthalten, besteht und einer Kathodenbeschichtung. Der Kathodenträger enthält die Heizung und die Basis mit der Deckschicht. Als Kathodenträger können die aus dem Stand der Technik bekannten Konstruktionen und Materialien verwendet werden.An oxide cathode according to the invention comprises a cathode support having a cathode base and a cover layer consisting of ultrafine metal particles containing nickel and a cathode coating. The cathode support contains the heater and the base with the topcoat. As the cathode support, the structures and materials known from the prior art can be used.

In der in Fig. 1 gezeigten Ausführungsform der Erfindung besteht die Oxidkathode aus einen Kathodenträger, d.h. einem zylindrischen Röhrchen 3, in das der Heizdraht 4 eingesetzt ist, aus einer Kappe 2, die die Kathodenbasis bildet, mit der Deckschicht 7 und aus einer Kathodenbeschichtung 1, die den eigentlichen Kathodenkörper darstellt.In the embodiment of the invention shown in Fig. 1, the oxide cathode consists of a cathode support, i. a cylindrical tube 3, in which the heating wire 4 is inserted, from a cap 2, which forms the cathode base, with the cover layer 7 and from a cathode coating 1, which represents the actual cathode body.

Das Material der Kathodenbasis ist bevorzugt ein Metall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt. Üblicherweise wird eine Nickellegierung verwendet. Die Nickellegierungen für die Basis der erfindungsgemäßen Oxidkathoden können aus Nickel mit einem Legierungsanteil aus einem reduzierend wirkenden Aktivatorelement, ausgewählt aus der Gruppe Magnesium, Mangan, Eisen, Silicium, Wolfram, Molybdän, Chrom, Titan, Hafnium, Zirkon und Aluminium bestehen. Nachdem auch die Kathodenbeschichtung auch Aktivatorelemente enthält, kann die Menge an Aktivatorelementen in dem Material der Kathodenbasis niedrig gehalten werden. Ein Legierungsanteil von 0.05 bis 0.8 % Aktivatormetall in dem Material für die Kathodenbasis ist bevorzugt.The material of the cathode base is preferably a metal selected from the group Ni, Co, Ir, Re, Pd, Rh and Pt. Usually, a nickel alloy is used. The nickel alloys for the base of the oxide cathodes according to the invention may consist of nickel with an alloying component of a reducing activator element selected from the group of magnesium, manganese, iron, silicon, tungsten, molybdenum, chromium, titanium, hafnium, zirconium and aluminum. Since the cathode coating also contains activator elements, the amount of activator elements in the cathode base material can be kept low. An alloying amount of 0.05 to 0.8% of activator metal in the cathode base material is preferred.

Die Kathodenbasis ist mit einer Deckschicht beschichtet, die aus ultrafeinen Metallpartikeln, die Nickel enthalten, besteht. Die Partikelgröße der ultrafeinen Partikel liegt unter 100 nm. Bevorzugt enthalten die ultrafeinen Partikel einen Aktivator ausgewählt aus der Gruppe Mg, Al, Mo, Ti, Si, Cr, Zr, Mg. Besonders bevorzugt ist es, wenn die Metallpartikel einen langsamen Aktivator ausgewählt der Gruppe Al, Mo, Ti und Si enthält. Die langsamen Aktivatoren werden bevorzugt in einer Menge von 1 bis 4 Gew.-% zugesetzt.The cathode base is coated with a topcoat consisting of ultrafine metal particles containing nickel. The particle size of the ultrafine particles is less than 100 nm. The ultrafine particles preferably contain an activator selected from the group consisting of Mg, Al, Mo, Ti, Si, Cr, Zr, Mg. It is particularly preferred if the metal particles comprise a slow activator Group Al, Mo, Ti and Si contains. The slow activators are preferably added in an amount of 1 to 4 wt .-%.

Der Kathodenbeschichtung enthält ein elektronenemittierendes Material, das aus einem Partikel-Partikel-Verbundwerkstoff besteht. Die Hauptkomponente des Partikel-Partikel-Verbundwerkstoffs in dem elektronenemittierenden Material sind Oxidpartikel 6, die ein Oxid ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium; und ein Erdalkalioxid ausgewählt aus der Gruppe der Oxide des Calciums, Strontiums und Bariums enthalten.The cathode coating contains an electron-emitting material that consists of a particle-particle composite. The main component of the particle-particle composite in the electron-emitting material are oxide particles 6 comprising an oxide selected from the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, Thulium, ytterbium and lutetium; and an alkaline earth oxide selected from the group of oxides of calcium, strontium and barium.

Die Oxidpartikel können Oxidpartikel mit Oxiden der Erdalkalimetall, die den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium dotiert sind, enthalten.The oxide particles may include oxide particles having alkaline earth metal oxides doped with the oxides of scandium, yttrium and lanthanides such as cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

Nach einer anderen Ausführungsform der Erfindung enthalten die Oxidpartikel Oxidpartikel mit Oxiden der Erdalkalimetall, und Oxidpartikel mit den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium.According to another embodiment of the invention, the oxide particles contain oxide particles with oxides of the alkaline earth metal, and oxide particles with the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

Als Erdalkalioxid ist Bariumoxid, zusammen mit Calciumoxid oder/und Strontiumoxid bevorzugt. Die Erdalkalioxide werden als ein physikalisches Gemenge von Erdalkalioxiden oder als binäre oder ternäre Mischkristalle der Erdalkalimetalloxide verwendet. Bevorzugt ist ein ternäres Erdalkalimischkristalloxid aus Bariumoxid, Strontiumoxid und Calciumoxid oder ein binäres Gemisch aus Bariumoxid und Calciumoxid.Barium oxide, together with calcium oxide or / and strontium oxide is preferred as the alkaline earth oxide. The alkaline earth oxides are used as a physical mixture of alkaline earth oxides or as binary or ternary mixed crystals of the alkaline earth metal oxides. Preferred is a ternary alkaline earth mixed crystal oxide of barium oxide, strontium oxide and calcium oxide or a binary mixture of barium oxide and calcium oxide.

Das Erdalkalioxid kann eine Dotierung aus einem Oxid ausgewählt aus den Oxiden des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium, z. B. in einer Menge von 10 bis maximal 1000 ppm, enthalten. Die Ionen des Scandiums, Yttriums und der Lanthanoiden besetzen Gitterplätze oder Zwischengitterplätze im Kristallgitter der Erdalkalimetalloxide. Bevorzugt wird Yttrium als Dotierung verwendet. Man erhält die dotierten Oxide durch Copräcipitation.The alkaline earth oxide may be doped with an oxide selected from the oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, e.g. B. in an amount of 10 to a maximum of 1000 ppm included. The ions of scandium, yttrium and lanthanides occupy lattice sites or interstitials in the crystal lattice of alkaline earth metal oxides. Yttrium is preferably used as doping. The doped oxides are obtained by coprecipitation.

Andererseits können Oxidpartikel der Erdalkalioxide und Oxidpartikel der Oxide des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium auch separat hergestellt werden und als physikalisches Gemenge verwendet werden.On the other hand, oxide particles of the alkaline earth oxides and oxide particles of the oxides of scandium, yttrium and lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium can also be prepared separately and used as a physical mixture become.

Der Partikel-Partikel-Verbundwerkstoff des elektronenemittierenden Materials enthält als zweite Komponente Metallpartikel 5, die das zweite Kathodenmetall enthalten. Das Material für die zweite Komponente ist eine Legierung aus einem zweiten Kathodenmetall ausgewählt aus der Gruppe Ni, Co, Ir, Re, Pd, Rh und Pt mit einem Aktivatormetall, ausgewählt aus der Gruppe Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.The particle-particle composite of the electron-emitting material contains, as a second component, metal particles 5 containing the second cathode metal. The material for the second component is an alloy of a second one Cathode metal selected from the group Ni, Co, Ir, Re, Pd, Rh and Pt with an activator metal selected from the group Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.

Für den Partikel-Partikel-Verbundwerkstoff der vorliegenden Erfindung können bevorzugt Metallpartikel mit einer kugeligen oder ellipsoidalen Kornform verwendet werden. Der mittlere Korndurchmesser beträgt bevorzugt 0.2 bis 5 µm. Es ist auch möglich, nadelförmige Metallpartikel mit einem maximalen Korndurchmesser von 10 bis 15 µm zu verwenden. Derartige nadelförmige Partikel können durch geeignete Abscheideverfahren vertikal zu der Kathodenbasis ausgerichtet werden.For the particulate-particle composite of the present invention, metal particles having a spherical or ellipsoidal grain shape may be preferably used. The mean grain diameter is preferably 0.2 to 5 microns. It is also possible to use needle-shaped metal particles having a maximum grain diameter of 10 to 15 μm. Such acicular particles may be aligned vertically to the cathode base by suitable deposition techniques.

Für Partikel mit einem kleinen Korndurchmesser sind die langsam diffundierenden Aktivatormetalle wie Mo und W in einer Konzentration von 2 bis 10 Gew.-% in der Legierung besonders geeignet. Umgekehrt eignen sich für Partikel mit größerem Korndurchmesser die schneller diffundierenden Aktivatormetalle wie Zr und Mg.For particles with a small grain diameter, the slowly diffusing activator metals such as Mo and W in a concentration of 2 to 10 wt .-% in the alloy are particularly suitable. Conversely, for particles with a larger grain diameter, the faster diffusing activator metals such as Zr and Mg are suitable.

Für die Deckschicht auf der Kathodenbasis können die ultrafeine Partikel, die Nickel oder Nickel und ein anderes Kathodenmetall enthalten, durch ein Laserablationsverfahren aus den entsprechenden Targets hergestellt werden. Diese Targets enthalten Kathodennickel, das mit Aktivatoren wie Mg. Al, Ti, Zr, Si, Cr, Zr und Mg legiert sein kann. Beispielsweise können die ultrafeinen Partikel für die Deckschicht separat hergestellt werden und durch ein übliches Beschichtungsverfahren auf die Kathodenbasis aufgebracht werden. Es ist auch möglich, die ultrafeinen Partikel für die Deckschicht direkt durch Laserablation auf der Kathodenbasis abzuscheiden. Es ist außerdem möglich, nasschemische oder Sol-Gel-Präparationsmethoden zur Herstellung der ultrafeinen Partikel zu verwenden.For the cathode-based capping layer, the ultrafine particles containing nickel or nickel and another cathode metal can be prepared from the respective targets by a laser ablation method. These targets contain cathode nickel, which can be alloyed with activators such as Mg.Al, Ti, Zr, Si, Cr, Zr, and Mg. For example, the ultrafine particles for the topcoat may be prepared separately and applied to the cathode base by a conventional coating process. It is also possible to deposit the ultrafine particles for the cover layer directly by laser ablation on the cathode base. It is also possible to use wet-chemical or sol-gel preparation methods to prepare the ultrafine particles.

Zur Herstellung der Rohmasse für die Kathodenbeschichtung werden die Carbonate der Erdalkalimetalle Calcium, Strontium und Barium miteinander gemahlen und gemischt. Typischerweise beträgt das Gewichtsverhältnis von Calciumcarbonat : Strontiumcarbonat : Bariumcarbonat : Zirkon gleich 25,2 : 31,5 : 40,3 : 3.oder1 :1.25:6 oder 1:12:22 oder 1:1.5:2.5 oder 1:4:6. Den Carbonaten werden ein oder mehrere Oxide des Scandiums, Yttriums und der Lanthanoiden Cer, Praseodym, Neodym, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium und Lutetium zugesetzt. Bevorzugt wird Y2O3 in einer Menge von 130ppm zugefügt.To produce the raw material for the cathode coating, the carbonates of the alkaline earth metals calcium, strontium and barium are ground together and mixed. Typically, the weight ratio of calcium carbonate: strontium carbonate: barium carbonate: zirconium is equal to 25.2: 31.5: 40.3: 3.or1: 1.25: 6 or 1:12:22 or 1: 1.5: 2.5 or 1: 4: 6 , One or more oxides of scandium, yttrium and the lanthanides cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium are added to the carbonates. Preferably, Y 2 O 3 is added in an amount of 130 ppm.

Carbonate, Oxide und Metallpartikel werden zur Rohmasse gemischt. Der Rohmasse kann noch eine Bindemittelzubereitung zugesetzt werden. Die Bindemittelzubereitung kann als Lösungsmittel Wasser Ethanol Ethylnitrat, Ethylacetat, oder Diethylacetat enthalten.Carbonates, oxides and metal particles are mixed into the raw material. The raw material can still be added to a binder preparation. The binder preparation may contain, as solvent, water, ethanol, ethyl nitrate, ethyl acetate, or diethyl acetate.

Die Rohmasse für die Kathodenbeschichtung wird dann durch Pinseln, Tauchen, kataphoretische Abscheidung oder Sprühen auf die Kathodenbasis aufgebracht.The raw material for the cathode coating is then applied to the cathode base by brushing, dipping, cataphoretic deposition or spraying.

Die Dicke der Kathodenbeschichtung beträgt bevorzugt 30 bis 80 µm.The thickness of the cathode coating is preferably 30 to 80 μm.

Die beschichteten Oxidkathoden werden in die Kathodenstrahlröhre eingebaut. Während des Evakuierens der Kathodenstrahlröhre werden die Kathoden formiert. Dazu werden sie auf eine Temperatur von 1000°C bis 1200°C erhitzt. Bei dieser Temperatur werden die Erdalkalicarbonate zu den Erdalkalioxiden unter Freisetzung von CO und CO2 umgesetzt und bilden dann einen porösen Sinterkörper. Nach diesem "Abbrennen" der Kathoden erfolgt die Aktivierung, die den Zweck hat, überschüssiges, in die Oxide eingelagertes, elementares Erdalkalimetall zu liefern. Das überschüssige Erdalkalimetall entsteht durch Reduktion von Erdalkalimetalloxid. Bei der eigentlichen Reduktionsaktivierung wird das Erdalkalioxid durch das freigesetzte CO oder Aktivatormetall reduziert. Hinzu kommt eine Stromaktivierung, die die Bildung des erforderliche freien Erdalkalimetall durch elektrolytische Vorgänge bei hohen Temperaturen erzeugt.The coated oxide cathodes are installed in the cathode ray tube. During the evacuation of the cathode ray tube, the cathodes are formed. For this purpose, they are heated to a temperature of 1000 ° C to 1200 ° C. At this temperature, the alkaline earth carbonates are converted to the alkaline earth oxides to release CO and CO 2 and then form a porous sintered body. After this "burning off" of the cathodes is the activation, which has the purpose to provide excess, embedded in the oxides, elemental alkaline earth metal. The excess alkaline earth metal is formed by reduction of alkaline earth metal oxide. During the actual reduction activation, the alkaline earth oxide is reduced by the liberated CO or activator metal. In addition, there is a current activation, which generates the formation of the required free alkaline earth metal by electrolytic processes at high temperatures.

Das fertig formierte, elektronenemittierende Material kann bevorzugt 1 bis 5 Gew.-% Metallpartikel enthalten.The finished-formed, electron-emitting material may preferably contain 1 to 5 wt .-% metal particles.

Ausführungsbeispiel 1Embodiment 1

Wie in Fig. 1 gezeigt, weist eine Kathode für eine Kathodenröhre gemäß einer ersten Ausführungsform der Erfindung eine kappenförmige Kathodenbasis, die aus einer Legierung von Nickel mit 0.12 Gew.-% Mg, 0.06 Gew.-% Al und 2.0 Gew.-% W besteht, auf. Die Kathodenbasis befindet sich am oberen Ende eines zylindrischen Kathodenträgers (Muffe), in der die Heizung montiert ist.As shown in Fig. 1, a cathode tube cathode according to a first embodiment of the invention has a cap-shaped cathode base made of an alloy of nickel with 0.12 wt% Mg, 0.06 wt% Al, and 2.0 wt% W insists on. The cathode base is located at the top of a cylindrical cathode support (sleeve) in which the heater is mounted.

Für die Deckschicht, die aus ultrafeinen Metallpartikel, die Nickel enthalten, besteht, wird die Kathodenbasis in die Ablationskammer einer Laserablationsanlage gebracht. Ein Excimer-Laserstrahl wird bei einem Druck von einigen mbar auf ein rotierendes zylindrisches Target aus Kathodennickel gerichtet, das eine geeignete Menge von Aktivatoren enthält, und ablatiert dies. Eine Plasmafackel mit ablatierten ultrafeinen Partikeln bildet sich über dem Target. Diese ablatierten ultrafeinen Partikel werden mittels eines Tragergasstroms aus Ar/H2 zu der Kathodenbasis transportiert und dort abgeschieden. Das Trägergas aus Ar/H2 verhindert eine Oxidation der Partikel während des Transportes. Andere Inertgase können dafür auch geeignet sein. Nach einer Abwandlung des Verfahrens beginnt man die Laserablation bei niedrigen Drücken um 10-2 mbar und niedrigem Tragergasdruck, wodurch zunächst eine feinkörnige kompakte Schicht aus Nickelpartikeln entsteht. Anschließend erhöht man den Gasdruck und den Trägergasstrom, um eine Abscheidung von ultrafeinen Partikeln zu erreichen. Dadurch lässt sich ein kontinuierlicher Übergang von kompakten Schichten zu Schichten mit ultrafeinen Partikeln erzeugen.For the cover layer, which consists of ultrafine metal particles containing nickel, the cathode base is placed in the ablation chamber of a laser ablation unit. An excimer laser beam is directed at a pressure of a few mbars onto a rotating cylindrical cathode-nickel target containing an appropriate amount of activators and ablates it. A plasma torch with ablated ultrafine particles forms over the target. These ablated ultrafine particles are transported to the cathode base by means of a carrier gas flow of Ar / H 2 and deposited there. The carrier gas of Ar / H 2 prevents oxidation of the particles during transport. Other inert gases may also be suitable for this purpose. According to a modification of the method, the laser ablation is started at low pressures by 10 -2 mbar and low carrier gas pressure, whereby initially a fine-grained compact layer of nickel particles is formed. Subsequently, the gas pressure and the carrier gas flow are increased to achieve deposition of ultrafine particles. This allows a continuous transition from compact layers to ultra-fine particle layers.

Die Kathode weist auf der Oberseite der Kathodenbasis eine Kathodenbeschichtung auf. Um die Kathodenbeschichtung zu bilden, wird die Kathodenbasis zunächst gereinigt. Dann werden eine 2.0 Gew.-% Metallpartikel und 98 Gew.-% Pulver einer Ausgangsverbindung für die Oxidpartikel mit 130 ppm Yttriumoxid in einer Lösung aus Ethanol, Butylacetat und Nitrocellulose suspendiert.The cathode has a cathode coating on top of the cathode base. To form the cathode coating, the cathode base is first cleaned. Then, 2.0 wt% metal particles and 98 wt% powder of a starting compound for the oxide particles containing 130 ppm of yttria are suspended in a solution of ethanol, butyl acetate and nitrocellulose.

Die Metallpartikel bestehen aus einer Legierung von Nickel mit 0.02 Gew.-% Al, 3.0 Gew.-% W und 6.0 Gew.-% Mo. Die Metallpartikel haben eine nadelige Kornform mit einer mittleren Nadellänge von 3 ± 2 µm. Das Pulver mit den Ausgangsverbindungen für die Oxidpartikel besteht aus Barium-Strontium-Carbonat mit 130 ppm Yttriumoxid. Diese Suspension wird auf die Kathodenbasis aufgesprüht.The metal particles consist of an alloy of nickel with 0.02 wt .-% Al, 3.0 wt .-% W and 6.0 wt .-% Mo. The metal particles have a needle-like grain shape with a mean needle length of 3 ± 2 microns. The powder with the starting compounds for the oxide particles consists of barium strontium carbonate with 130 ppm yttrium oxide. This suspension is sprayed onto the cathode base.

Die Schicht wird bei einer Temperatur von 650 bis 1100°C formiert, um die Legierung und Diffusion zwischen dem Kathodenmetall der Metallbasis und den Metallpartikeln zu bewirken.The layer is formed at a temperature of 650 to 1100 ° C to effect alloying and diffusion between the metal base of the metal base and the metal particles.

Die so gebildete Kathode hat eine Gleichstrombelastbarkeit von 4 A/cm2 bei einer Lebensdauer von 20 000 h und einen Röhreninnendruck von 2 * 10-9 bar.The cathode thus formed has a direct current capability of 4 A / cm 2 with a lifetime of 20,000 h and a tube internal pressure of 2 * 10 -9 bar.

Claims (18)

  1. An oxide cathode which comprises a cathode carrier having a cathode base (2) of a first cathode metal and a cathode coating (1) of an electron-emitting material containing a particle-particle composite material of oxide particles (6) and metal particles (5), which oxide particles comprise an oxide selected from among the oxides of scandium, yttrium and the lanthanoids cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and an alkaline earth oxide selected from the group consisting of the oxides of calcium, strontium and barium, characterized in that the cathode base (2) consists of a first cathode metal with a covering layer of ultrafine metal particles that comprise nickel, and in that the metal particles (5) comprise a second cathode metal selected from the group consisting of Ni, Co, Ir, Pd, Rh and Pt.
  2. An oxide cathode as claimed in claim 1, characterized in that the first cathode metal comprises a metal selected from the group consisting of Ni, Co, Ir, Re, Pd, Rh and Pt.
  3. An oxide cathode as claimed in claim 1, characterized in that the first cathode metal contains an alloy of a metal selected from the group consisting ofNi, Co, Ir, Re, Pd, Rh, Pt and an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  4. An oxide cathode as claimed in claim 1, characterized in that the covering layer additionally comprises an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  5. An oxide cathode as claimed in claim 1, characterized in that the ultrafine metal particles comprise a slow activator selected from the group consisting of Al, Mo, Ti and Si.
  6. An oxide cathode as claimed in claim 5, characterized in that the slow activators are added in a quantity ranging from 1 to 4% by weight.
  7. An oxide cathode as claimed in claim 1, characterized in that the metal particles (5) in the electron-emitting material comprise an alloy of a second cathode metal selected from the group consisting ofNi, Co, Ir, Re, Pd, Rh, Pt and an activator metal selected from the group consisting of Mg, Mn, Fe, Si, W, Mo, Cr, Ti, Hf, Zr, Al.
  8. An oxide cathode as claimed in claim 1, characterized in that the oxide particles (6) comprise oxide particles of an alkaline earth oxide selected from the group of oxides of calcium, strontium and barium, which is doped with an oxide selected from among the oxides of scandium, yttrium and the lanthanoids cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
  9. An oxide cathode as claimed in claim 1, characterized in that the oxide particles (6) comprise oxide particles of an alkaline earth oxide selected from the group consisting of the oxides of calcium, strontium and barium, which is doped with one of the oxides of yttrium.
  10. An oxide cathode as claimed in claim 1, characterized in that the electron-emitting material comprises metal particles (5) in a quantity ranging from 1 to 5% by weight.
  11. An oxide cathode as claimed in claim 1, characterized in that the electron-emitting material comprises nickel particles (5) in a quantity of 2.5% by weight.
  12. An oxide cathode as claimed in claim 1, characterized in that the metal particles (5) are shaped so as to be ellipsoidal or spherical.
  13. An oxide cathode as claimed in claim 1, characterized in that the metal particles are needle-shaped.
  14. An oxide cathode as claimed in claim 1, characterized in that the average particle diameter of the metal particles (5) ranges from 0.2 to 5.0 µm.
  15. An oxide cathode as claimed in claim 1, characterized in that the metal particles (5) are embedded in the particle-particle composite in an oriented manner.
  16. An oxide cathode as claimed in claim 1, characterized in that the metal particles (5) are embedded in the particle-particle composite so as to extend vertically to the surface of the cathode base (2).
  17. An oxide cathode as claimed in claim 1, characterized in that the metal particles (5) are embedded in the particle-particle composite with a concentration gradient.
  18. A cathode ray tube provided with an oxide cathode as claimed in claim 1.
EP01980367A 2000-09-19 2001-09-11 Oxide cathode Expired - Lifetime EP1232511B1 (en)

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PCT/EP2001/010453 WO2002025681A1 (en) 2000-09-19 2001-09-11 Isahode ray tube having an oxide cathode
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Families Citing this family (9)

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KR100449759B1 (en) * 2002-03-21 2004-09-22 삼성에스디아이 주식회사 Cathode for electron tube and preparing method thereof
GB0230125D0 (en) * 2002-12-24 2003-01-29 Lg Philips Displays Netherland Oxide cathode
US20060068196A1 (en) * 2004-09-24 2006-03-30 Kabushiki Kaisha Toshiba High-frequency magnetic material, producing method for the same and high-frequency magnetic device
DE102008020164A1 (en) * 2008-04-22 2009-10-29 Siemens Aktiengesellschaft Cathode with a flat emitter
CN101447376B (en) * 2008-12-31 2010-09-01 北京工业大学 Y2O3-Lu2O3 system composite rare earth-molybdenum electron emission material and preparation method thereof
CN103050347A (en) * 2011-10-13 2013-04-17 中国科学院电子学研究所 Method for preparing nickel-scandium (Ni-Sc) sponge oxide cathode
CN103700557B (en) * 2013-12-24 2016-03-30 北京工业大学 A kind of carbonization rare-earth oxidation lutetium doping molybdenum cathode material and preparation method thereof
JP6285254B2 (en) * 2014-04-02 2018-02-28 大学共同利用機関法人 高エネルギー加速器研究機構 Electron beam generating cathode member and manufacturing method thereof
CN110690085B (en) * 2019-10-24 2022-03-11 成都国光电气股份有限公司 Method for preparing six-membered cathode emission material

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1270890A (en) * 1985-07-19 1990-06-26 Keiji Watanabe Cathode for electron tube
JPS62165832A (en) * 1986-01-18 1987-07-22 Mitsubishi Electric Corp Cathode for electron tube
KR910009660B1 (en) * 1988-02-23 1991-11-25 미쓰비시전기 주식회사 Cathode for electron tube
JP2758244B2 (en) * 1990-03-07 1998-05-28 三菱電機株式会社 Cathode for electron tube
DE4207220A1 (en) * 1992-03-07 1993-09-09 Philips Patentverwaltung SOLID ELEMENT FOR A THERMIONIC CATHODE
SG44617A1 (en) * 1993-08-20 1997-12-19 Samsung Display Devices Co Ltd Oxide cathode for electron tube
DE19527723A1 (en) * 1995-07-31 1997-02-06 Philips Patentverwaltung Electric discharge tube or discharge lamp and Scandat supply cathode
JP2876591B2 (en) * 1996-11-29 1999-03-31 三菱電機株式会社 Cathode for electron tube
KR100249714B1 (en) * 1997-12-30 2000-03-15 손욱 Cathode used in an electron gun
KR100268243B1 (en) * 1997-12-30 2000-10-16 김순택 Cathod used in an electron gun
JPH11204019A (en) 1998-01-09 1999-07-30 Sony Corp Oxide cathode
KR20000038644A (en) * 1998-12-08 2000-07-05 김순택 Cathode for electric gun
JP2001345041A (en) * 2000-06-01 2001-12-14 Mitsubishi Electric Corp Cathode for electron tube

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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