JPH01143116A - Electronic tube cathode - Google Patents
Electronic tube cathodeInfo
- Publication number
- JPH01143116A JPH01143116A JP62300667A JP30066787A JPH01143116A JP H01143116 A JPH01143116 A JP H01143116A JP 62300667 A JP62300667 A JP 62300667A JP 30066787 A JP30066787 A JP 30066787A JP H01143116 A JPH01143116 A JP H01143116A
- Authority
- JP
- Japan
- Prior art keywords
- nickel
- electron
- oxide
- sintered layer
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 42
- HYXGAEYDKFCVMU-UHFFFAOYSA-N scandium oxide Chemical compound O=[Sc]O[Sc]=O HYXGAEYDKFCVMU-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052788 barium Inorganic materials 0.000 claims abstract description 14
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 14
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 11
- 239000010703 silicon Substances 0.000 claims abstract description 11
- 239000002245 particle Substances 0.000 claims abstract description 4
- 239000000463 material Substances 0.000 claims description 24
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 4
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims 1
- 239000010953 base metal Substances 0.000 abstract description 27
- 229910052751 metal Inorganic materials 0.000 abstract description 18
- 239000002184 metal Substances 0.000 abstract description 18
- 239000000126 substance Substances 0.000 abstract description 8
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 abstract description 6
- 239000011575 calcium Substances 0.000 abstract description 4
- 229910052791 calcium Inorganic materials 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract description 3
- 229910052712 strontium Inorganic materials 0.000 abstract description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 abstract description 2
- 230000009471 action Effects 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 abstract description 2
- 230000002829 reductive effect Effects 0.000 abstract 2
- 239000002075 main ingredient Substances 0.000 abstract 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 18
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 13
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Inorganic materials [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 12
- 229910002092 carbon dioxide Inorganic materials 0.000 description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 8
- 239000001569 carbon dioxide Substances 0.000 description 8
- 150000002739 metals Chemical class 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 239000011777 magnesium Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000000020 Nitrocellulose Substances 0.000 description 5
- 229920001220 nitrocellulos Polymers 0.000 description 5
- 238000006722 reduction reaction Methods 0.000 description 5
- 239000007795 chemical reaction product Substances 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- -1 alkaline earth metal carbonate Chemical class 0.000 description 3
- 229910052916 barium silicate Inorganic materials 0.000 description 3
- HMOQPOVBDRFNIU-UHFFFAOYSA-N barium(2+);dioxido(oxo)silane Chemical compound [Ba+2].[O-][Si]([O-])=O HMOQPOVBDRFNIU-UHFFFAOYSA-N 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 2
- 229910001863 barium hydroxide Inorganic materials 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000004070 electrodeposition Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 229910001120 nichrome Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229910052706 scandium Inorganic materials 0.000 description 1
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
Landscapes
- Solid Thermionic Cathode (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、受像管などの電子管に具備される陰極に係
わるもので、陰極から放出される電流密度の向上を図っ
たものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cathode included in an electron tube such as a picture tube, and is intended to improve the current density emitted from the cathode.
従来、受像管などの電子管に具備される陰極には、ニッ
ケル（Ｎｉ ）を主成分としマグネシウム（Ｍｇ）、シ
リコン（Ｓｉ）などの還元性金属を微量含有した基体金
属上にバリウム（Ｂａ）を含むアルカリ土類金属酸化物
を被着形成した、所謂、酸化物陰極が多用されてきた。Conventionally, cathodes included in electron tubes such as picture tubes are made by coating barium (Ba) on a base metal that is mainly composed of nickel (Ni) and contains small amounts of reducing metals such as magnesium (Mg) and silicon (Si). So-called oxide cathodes, in which alkaline earth metal oxides containing alkaline earth metals are deposited, have been widely used.
この酸化物陰極はアルカリ土類金属の炭酸塩を熱分解し
て酸化物に変換せしめ、次に還元性金属と酸化物とを反
応させながら酸化物から遊離京子を生成し９子放射のド
ナー（源）として電子放射を行わせるようにしたもので
ある。このような複雑な手順を経る理由は、Ｂａは電子
放射能力には優れているが非常に活性であるため空気中
の水分と反応して水酸化バリウム（Ｂａ（ＯＨ）ｚ ）
となり、この水酸化バリウム（Ｂａ（ＯＲ）！ ）から
遊離バリウＡ （Ｂａ）を電子管内に生成することは困
難であるので、化学的に安定である炭酸塩を出発物質に
せざるを得ないからである。炭酸塩にはＢａＣ０，の単
元のものと（Ｂａ、 Ｓｒ 、 Ｃａ ）ω３などの復
元のものがあるが、ドナーを形成する活性化の基本的な
機構は同じであるから、理解を容易にするため以下、単
元炭酸塩を例にし。て詳細に説明する。This oxide cathode thermally decomposes alkaline earth metal carbonate to convert it into an oxide, and then reacts the reducing metal with the oxide to generate free Kyoko from the oxide, which is the donor for 9-ion radiation ( It is designed to emit electrons as a source (source). The reason for such a complicated procedure is that although Ba has excellent electron emission ability, it is very active and reacts with moisture in the air to form barium hydroxide (Ba(OH)z).
Since it is difficult to generate free barium A (Ba) from this barium hydroxide (Ba(OR)!) in an electron tube, we have no choice but to use chemically stable carbonate as the starting material. It is. There are two types of carbonates: unitary ones such as BaC0, and restored ones such as (Ba, Sr, Ca)ω3, but the basic mechanism of activation to form donors is the same, so it is easier to understand. Therefore, below we will use a unitary carbonate as an example. This will be explained in detail.
第３図は従来の酸化物陰極の一例を示す概略構速断面図
であって、（１）は基体金属、（２）はスリーブ、（３
）は加熱用のヒータ、（５）は基体金属（１）の表面に
被着形成された炭酸バリウム（ＢａＣＯｌ）からなる電
子放射物質である。この電子放射物質（５）は、有機溶
剤に溶解したニトロセルロース等のバインダに炭酸バリ
ウム（ＢａＣＯ３）を混合し、吹きつけ、電着、あるい
は塗布等の方法で被着形成する。FIG. 3 is a schematic cross-sectional view showing an example of a conventional oxide cathode, in which (1) is the base metal, (2) is the sleeve, and (3) is the base metal.
) is a heater for heating, and (5) is an electron emitting material made of barium carbonate (BaCOl) deposited on the surface of the base metal (1). The electron emitting material (5) is formed by mixing barium carbonate (BaCO3) with a binder such as nitrocellulose dissolved in an organic solvent and depositing the mixture by spraying, electrodeposition, coating, or the like.
このように構成された酸化物陰極は、電子管内に組み込
まれ、電子管内を真空にするための排気工程でヒータ（
３）によって約１０００°Ｃに加熱昇温され、炭酸バリ
ウム（ＢａＣ０３）が次式のように熱分解される。The oxide cathode configured in this way is incorporated into an electron tube, and a heater (
3), the temperature is raised to about 1000°C, and barium carbonate (BaC03) is thermally decomposed as shown in the following equation.
ＢａＣ０，→ＢａＯ＋ＣＯ２・・−（１）この反応によ
って生成された炭酸ガス（ＣＯ３）は真空ポンプによっ
て電子管外に排出される。同時にニトロセルロース等の
樹脂も熱分解されて気体となり、炭酸ガスと共に管外に
排出される。BaC0,→BaO+CO2...-(1) Carbon dioxide (CO3) generated by this reaction is discharged outside the electron tube by a vacuum pump. At the same time, resins such as nitrocellulose are also thermally decomposed and turned into gases, which are discharged from the tube together with carbon dioxide gas.
第（１）式の反応によって、電子放射物質（５）の炭酸
バリウム（ＢａＣＯ，）は酸化バリウム（Ｂａｄ）に変
換される。この反応の際に、従来の酸化物陰極では、管
内の炭酸ガス（ＣＯｚ）、酸漿（０，）等の酸化性雰囲
気のもとで、基体金属（１）の表面でニッケルαｉ）と
共に、還元反応の重要な役割を担う還元性金属のシリコ
ン（Ｓｉ）やマグネシウム絢）も共に酸化されるという
欠点がある。By the reaction of equation (1), barium carbonate (BaCO,), which is the electron emitting substance (5), is converted to barium oxide (Bad). During this reaction, in a conventional oxide cathode, under an oxidizing atmosphere such as carbon dioxide gas (COz) and acid plasma (0,) inside the tube, reduction occurs together with nickel αi) on the surface of the base metal (1). The drawback is that the reducing metals silicon (Si) and magnesium (Si) that play an important role in the reaction are also oxidized.
第４図は基体金属（１）と電子放射物質（５）の接合近
傍を詳細に説明するための部分拡大断面図である。FIG. 4 is a partially enlarged sectional view for explaining in detail the vicinity of the junction between the base metal (1) and the electron emitting material (5).
一般に酸化バリウムは棒状の微小な結晶（８）が凝集し
て数ミクロンないし数十ミクロンの大きさの結晶粒（９
）となる。結晶粒間には適度の間隙ＣＬＩを形成した多
孔質の電子放射物質（５）を作るように配慮されている
。この酸化バリウム（Ｂａｄ）は基体金属（１）と接曽
する界面ａυに於て、前記還元性金属のシリコン（Ｓｉ
）やマグネシウム（Ｍｇ）と反応、遊離バリウム（Ｂ
ａ）を生成する。これらの還元性金属は基体金属（１）
のニッケル（Ｎｉ）の結晶粒界（７）を拡散移動し、界
面（ｌＩυ近傍で還元反応を行う。反応例を次に示す。In general, barium oxide is made by agglomerating rod-shaped microcrystals (8) into crystal grains (9) with a size of several microns to several tens of microns.
). Care is taken to create a porous electron emitting material (5) with appropriate gaps CLI between crystal grains. This barium oxide (Bad) is deposited on the reducing metal silicon (Si) at the interface aυ in contact with the base metal (1).
) and magnesium (Mg), free barium (B
a) Generate. These reducing metals are base metals (1)
The nickel (Ni) is diffused through the grain boundaries (7), and a reduction reaction occurs near the interface (lIυ).An example of the reaction is shown below.
ｚＢａＯ＋ Ｓｉ −＋ ｚＢａ ＋ ５ｉ０２−・−
−−−−・−（２）ＢａＯ＋ Ｍｇ −Ｂａ ＋ＭｇＯ
−−−−・−−−−（３）この遊離バリウム（Ｂａ）が
電子放射のドナーとなって作用する。この際、次の反応
も同時に起こる。zBaO+ Si −+ zBa + 5i02−・−
−−−・−(2) BaO+ Mg −Ba +MgO
-----・---- (3) This free barium (Ba) acts as a donor for electron emission. At this time, the following reactions also occur simultaneously.
Ｓｉｎ、 ＋ ｚＢａｏ −＋ Ｂａ、５ｉ０． ・・
−・・−・−（４）以上のように、ドナーは電子放射物
質（５）と基体金属（１）の接合面で生成され、電子放
射物質（５）の間隙（１（ｌを移動し、その表面に出て
電子放射の役を担うが、蒸発したり、電子管内の残留ガ
スであるω。Sin, + zBao −+ Ba, 5i0.・・・
−・・−・−(4) As described above, the donor is generated at the joint surface of the electron emitting material (5) and the base metal (1), and the donor moves through the gap (1(l)) of the electron emitting material (5). , which comes out to the surface and plays the role of electron emission, but ω evaporates or is a residual gas inside the electron tube.
Ｃｏ２．Ｏ，、Ｈ，０等と反応して消滅するので、絶え
ず上記のような反応を行って補給する必要があり、陰極
は使用中宮にこの還元反応を行っている。この補給と消
滅のバランスを取るために、一般に、この種の陰極は約
８００°Ｃの高温で使用される。Co2. Since it reacts with O, H, 0, etc. and disappears, it is necessary to constantly perform the above reaction and replenish it, and the cathode performs this reduction reaction during use. To balance this replenishment and depletion, cathodes of this type are generally used at high temperatures of about 800°C.
陰極の使用中、第（２）、（４）式、（７） Ｓｉｎ、
、 Ｂａ、５ｉｎ４等の反応生成物備が電子放射物質
（５）と基体金属（１）の接合面である界面（ロ）で生
成され、界面αηや結晶粒界（７）にどんどん蓄積され
てＳｉなどの通る障壁（一般に、これを中間層と呼ぶ）
となり、反応は次第に遅れドナーであるＢａの生成が困
難となる。During use of the cathode, equations (2) and (4), (7) Sin,
, Ba, 5in4, etc. are generated at the interface (b), which is the joint surface between the electron emitting material (5) and the base metal (1), and are rapidly accumulated at the interface αη and grain boundaries (7). Barrier through which Si etc. pass (generally called an intermediate layer)
As a result, the reaction is gradually delayed and it becomes difficult to generate Ba, which is a donor.
この中間層は高抵抗値を有し放射電子電流の流れを妨げ
る。このような問題点に対して、第５図に示すような、
酸化スカンジウム（ＳｃｔＯｇ）（転）を電子放射物質
（５）の中に分散させるという提案（特開昭６２−２２
３４７）がある。これはスカンジウム（Ｓｃ）によって
Ｂａ、５ｉ０４などの反応生成物＠を解離する作用があ
ると考えられるものである。また、別の提案（ＵＳＰ
４３６９３９２）として第６図に示すようにニッケル粉
末の焼結層（６）の中に電子放射物質（５）を含有させ
たものもある。これは、焼結層（６）によって中間層が
生成しても実質の抵抗値を下げようとしたものである。This intermediate layer has a high resistance value and impedes the flow of radiated electron current. To address these problems, as shown in Figure 5,
Proposal to disperse scandium oxide (SctOg) in an electron-emitting substance (5) (Japanese Patent Laid-Open No. 62-22
347). This is thought to be due to the effect of scandium (Sc) dissociating reaction products such as Ba and 5i04. Also, another proposal (USP
4369392) in which an electron-emitting substance (5) is contained in a sintered layer (6) of nickel powder, as shown in FIG. This is intended to lower the actual resistance value even if an intermediate layer is formed by the sintered layer (6).
このように、従来の電子管陰極においては、電子放射源
のドナーを形成するための炭酸塩の分解、還元の反応作
用中に還元性金属の酸化と反応生成物の蓄積が起こり、
また、動作中に基体金属（１）と電子放射物質（５）の
界面０υ近傍、特に基体金属（１）の表面近傍のニッケ
ル結晶粒界（７）に反応生成物が蓄積されるので放射電
子流および電子放射物質（５）への還元性金属の拡散補
給が次第に妨げられ、高電流密度下の十分な電子放射特
性が長時間にわたって得られないという欠点がある。上
記提案の酸化スカンジウム分散型陰極（特開昭６２−２
２３４７）およびニッケル焼結型陰極（ＵＳＰ ４３６
９３９２）はこれらの欠点に対処するものであるが、長
時間の動作に耐え得る電流密度の限界が２Ａ／ｃｎｌで
あり高解像度あるいは高輝度用の受像管への適用には問
題があった。As described above, in conventional electron tube cathodes, oxidation of reducing metals and accumulation of reaction products occur during the decomposition and reduction reactions of carbonates to form donors for electron emission sources.
In addition, during operation, reaction products accumulate near the 0υ interface between the base metal (1) and the electron emitting material (5), especially at the nickel grain boundaries (7) near the surface of the base metal (1), so the emitted electrons The disadvantage is that the diffusion and replenishment of reducing metals into the current and electron emitting material (5) are gradually hindered, and sufficient electron emitting properties under high current density cannot be obtained for a long time. Scandium oxide dispersed cathode proposed above (Japanese Unexamined Patent Publication No. 62-2
2347) and nickel sintered cathode (USP 436
9392) addresses these drawbacks, but the current density limit that can withstand long-term operation is 2 A/cnl, which poses a problem in its application to high-resolution or high-brightness picture tubes.
この発明に係る電子管陰極は、ニッケルの基体金属にニ
ッケル粉末焼結層を設（）、更にこのニッケル粉末焼結
層の中の空孔部にアルカリ土類金属酸化物と酸化スカン
ジウムとの混合物とからなる電子放射物質を含有さすこ
とにより長時間に渡つて安定した高電流密度動作を得よ
うとするものである。In the electron tube cathode according to the present invention, a sintered nickel powder layer is provided on a base metal of nickel (), and a mixture of an alkaline earth metal oxide and scandium oxide is added to the pores in the sintered nickel powder layer. By containing an electron-emitting substance consisting of a material containing an electron-emitting material, it is attempted to obtain stable high current density operation over a long period of time.
この発明における、ニッケル粉末焼結層は基体金属と電
子放射面との間の電気抵抗値を低減することができ、更
に、電子放射物質中の酸化スカンジウムは基体金属ある
いはニッケル粉末の表面近傍で生成される中間層物質の
形成を防止することができる。In this invention, the nickel powder sintered layer can reduce the electrical resistance between the base metal and the electron emitting surface, and furthermore, scandium oxide in the electron emitting material is generated near the surface of the base metal or nickel powder. It is possible to prevent the formation of an intermediate layer material.
以下、この発明の一実施例を図によって説明する。 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
第１図は、この発明の電子管陰極の一実施例を示す概略
構造断面図であって、カップ状の基体金属（１）が筒状
のスリーブ（２）に接続され、その内部にはヒータ（３
）が配備され加熱昇温する構成となっている。基体金属
（１）は少なくともシリコン（Ｓｉ）を還元性金属とし
て含有したニッケル（Ｎｉ ）である。スリーブ（２）
はニクロム（Ｎｉ−Ｃｒ）から構成される。基体金属（
１）の表面には、少なくともシリコン（Ｓｉ）のような
還元性金属を含有したニッケル（Ｎｉ ）からなる粒子
の焼結層（２）を被着形成する。この焼結層（資）は平
均粒径１５〜３０ミクロンのニッケル粉末をニトロセル
ロースと混合して吹き付は等の方法により、約０．１ｍ
の厚さになるように基体金属（１）の上に被着形成する
。次に、水素雰囲気中で約１０００°Ｃ１１０分間の熱
処理を行う事によりニッケル粉末相互およびニッケル粉
末と基体金７ｉ （１）との焼結が起こり焼結層（６）
が構成される。焼結層的の空孔率は３０〜６０％で、こ
の空孔の中に電子放射物質（５）を充填する。この電子
放射物質（５）は少なくともバリウム（＆）を含有し、
他にストロンチウム（Ｓｒ）あるいはカルシウム（Ｃａ
）を含むアルカリ土類金属酸化物６υを主成分とし、０
．１〜２０重量パーセントの酸化スカンジウム６ｚを分
散させたものである。この電子放射物質（５）の充填方
法は、有機溶剤に溶解したニトロセルロースの溶液にア
ルカリ土類金属炭酸塩と酸化スカンジウムを所望の重量
パーセント混合して懸濁液とし、ボールミルなどの方法
により粉砕混合し、次に浸漬法、吹き付は法、電着法、
塗布法等により被着形成する。焼結層的よりはみだした
電子放射物質（５）は機械的に削り取って除去する。FIG. 1 is a schematic structural sectional view showing one embodiment of the electron tube cathode of the present invention, in which a cup-shaped base metal (1) is connected to a cylindrical sleeve (2), and a heater ( 3
) is installed to heat and raise the temperature. The base metal (1) is nickel (Ni) containing at least silicon (Si) as a reducing metal. Sleeve (2)
is composed of nichrome (Ni-Cr). Base metal (
A sintered layer (2) of particles made of nickel (Ni) containing at least a reducing metal such as silicon (Si) is deposited on the surface of 1). This sintered layer (material) is made by mixing nickel powder with an average particle size of 15 to 30 microns with nitrocellulose and spraying it to a length of about 0.1 m.
It is deposited on the base metal (1) to a thickness of . Next, heat treatment is performed at approximately 1000°C for 110 minutes in a hydrogen atmosphere to cause sintering of the nickel powder and the base gold 7i (1), resulting in a sintered layer (6).
is configured. The porosity of the sintered layer is 30 to 60%, and the electron emitting material (5) is filled into the pores. This electron emitting material (5) contains at least barium (&),
In addition, strontium (Sr) or calcium (Ca
), the main component is alkaline earth metal oxide 6υ including 0
．． 1 to 20 weight percent of scandium oxide 6z is dispersed therein. The method for filling this electron-emitting substance (5) is to mix alkaline earth metal carbonate and scandium oxide in a desired weight percentage with a solution of nitrocellulose dissolved in an organic solvent to form a suspension, and then pulverize the suspension using a method such as a ball mill. Mixing, then dipping method, spraying method, electrodeposition method,
Adhesion is formed by a coating method, etc. The electron emitting material (5) protruding from the sintered layer is mechanically scraped off and removed.
以上のような構成で製作した電子管陰極の電子放射源で
あるドナーの生成を行う工程を以下に詳しく説明する。The process of generating a donor, which is an electron emission source of the electron tube cathode manufactured with the above configuration, will be described in detail below.
この電子管陰極は電子管内に組み込まれ、電子管内を真
空にするための排気工程でヒータ（３）によって約１０
００°Ｃに昇温加熱されて炭酸バリウム（ＢａＣＯ，）
が次のように熱分解される０ＢａＣＯ，→ＢａＯ＋ＣＯ
，・＝−・・−＝＜１＞この反応で生じた炭酸ガス（Ｃ
Ｏりは電子管外に排出される。同時にニトロセルロース
も熱分解されて気体となり、炭酸ガス（ＣＯ，）と共に
電子管外に排出される。この反応によって、電子放射物
質（５）の中の炭酸バリウム（ＢａＣＯ，）は酸化バリ
ウム（Ｂａｄ）に変換する。This electron tube cathode is built into the electron tube, and is heated by a heater (3) during the evacuation process to create a vacuum inside the electron tube.
Barium carbonate (BaCO,) is heated to 00°C.
is thermally decomposed as follows: 0BaCO, →BaO+CO
,・=-・・-=<1> Carbon dioxide gas (C
Oxygen is discharged outside the electron tube. At the same time, nitrocellulose is also thermally decomposed and becomes a gas, which is discharged from the electron tube together with carbon dioxide (CO). Through this reaction, barium carbonate (BaCO,) in the electron emitting material (5) is converted to barium oxide (Bad).
陰極の使用中、陰極は約８００’Ｃに加熱され、（１）
式で生成した酸化バリウム（Ｂａｄ）は基体金ｇ （１
）および焼結層（２）の中の還元性金属と次のように反
応する。During use of the cathode, the cathode is heated to about 800'C, (1)
The barium oxide (Bad) produced by the formula is the base gold g (1
) and the reducing metal in the sintered layer (2) as follows.
ｚＢａｏ ＋ Ｓｉ ４ ｚＢａ ＋ ５ｉＯ１−−・
−・−−−−（２）この遊離バリウム（Ｂａ）が電子放
射のドナーとなって電子放射を担う。この発明の電子管
陰極では基体金属（１）および焼結層（２）の中に還元
性金属を含むため遊離バリウム（Ｂａ）の生成が活発に
行われるため、高電流密度動作の負荷に対して耐え得る
ことが可能となる。又、電流の一部は抵抗値の低い焼結
層的を通って流れるため、従来の陰極に比べて高電流密
度動作が可能となる。zBao + Si 4 zBa + 5iO1−-・
-・---(2) This free barium (Ba) becomes a donor for electron emission and is responsible for electron emission. In the electron tube cathode of the present invention, since the base metal (1) and the sintered layer (2) contain a reducing metal, free barium (Ba) is actively generated, so it can withstand the load of high current density operation. It becomes possible to endure. Also, because a portion of the current flows through the sintered layer, which has a low resistance value, higher current density operation is possible compared to conventional cathodes.
一方、長時間の動作中、次式の反応も行われる。On the other hand, during long-term operation, the following reaction also takes place.
Ｓｉｎｇ ＋ ２ＢａＯ−４ａ、ＳｉＯ，−・−・−・
・（４）この反応式の生成物である、バリウムシリケイ
ト（Ｂａ！５ｉ０４）は基体金属（１）および焼結ＩＱ
（２）の表面に徐々に蓄積され、シリコン（Ｓｉ）等の
還元性金属の通る障壁（中間層）となり、ドナーなる遊
離バリウムの生成が困難となるが、本発明の電子管陰極
では、電子放射物質（５）の中の酸化スカンジウム（財
）が次式に示すような反応を起こす。Sing + 2BaO-4a, SiO, -・-・-・
・(4) The product of this reaction formula, barium silicate (Ba!5i04), is a product of the base metal (1) and the sintered IQ
(2) gradually accumulates on the surface of barium and becomes a barrier (intermediate layer) through which reducing metals such as silicon (Si) pass, making it difficult to generate free barium as a donor. However, in the electron tube cathode of the present invention, electron emission Scandium oxide in substance (5) causes a reaction as shown in the following formula.
Ｓｃ、Ｏ，＋１ ｏＮｉ→ｚｓｃＮｉ ＋ ３０・・・
・・・・・・（５）９Ｂａ、Ｓ ｉ０４＋１６８ｄ’Ｊ
ｉ、→４Ｂａ、５ｃ４０．＋ ６Ｂａ ＋ ９８ｉ ＋
５ｏＮｉ・・−・＜８）このように、バリウムシリケイ
ト（Ｂａ、Ｓｉｎ、）は酸化スカンジウム（Ｓｃ、Ｏρ
とニッケル（Ｎｉ ）とにより分解されるので、電子放
射物質（５）と基体金［（１）あるいは焼結ノー（６）
との界面で蓄積されない。Sc, O, +1 oNi→zscNi + 30...
・・・・・・(5) 9Ba, S i04+168d'J
i, →4Ba, 5c40. + 6Ba + 98i +
5oNi...<8) In this way, barium silicate (Ba, Sin, ) is scandium oxide (Sc, Oρ
and nickel (Ni).
does not accumulate at the interface with
従って、従来の陰極のようにバリウムシリケイトなどの
反応生成物が基体金属や焼結層の表面に蓄積して還元性
金属の通る障壁となり、還元反応が次第に遅くなり、ド
ナーとなる遊離バリウムの生成が困難となることはない
。このように、高抵抗値の中間層がなく、また焼結層に
よる、基体金属と電子放射面間との導電性の向上、更に
、電子放射物質全域での遊離バリウムの生成作用などで
陰極を長時間に渡って高電流密度で作動させることがで
きた。Therefore, as in conventional cathodes, reaction products such as barium silicate accumulate on the surface of the base metal or sintered layer and act as a barrier for reducing metals to pass through, gradually slowing down the reduction reaction and producing free barium as a donor. is not difficult. In this way, there is no intermediate layer with a high resistance value, the sintered layer improves the conductivity between the base metal and the electron emitting surface, and the generation of free barium in the entire area of the electron emitting material makes it possible to improve the cathode. It was possible to operate at high current densities for long periods of time.
第２図は、電子放射電流の劣化状態を調べるため６００
０時間の寿命試験を行った結果である。この寿命試験で
は、電流密度５Ａ／ｄの高電流密度で動作させた。この
図に於て、■旧よ、この発明の陰極の特性を示すもので
、焼結層の中に、３％の酸化スカンジウムを分散させた
電子放射物質を充填したものである。四は、第５図に示
す従来の陰極で、電子放射物質層に３％の酸化スカンジ
ウムを分散したもの、嬶は、第３図に示す従来の酸化物
陰極の特性を示す。この図から明らかなように、本発明
の電子管陰極は６０００時間後、初期値の８０％に特性
が保たれ、寿命時間で表せば従来の陰極に比べて３〜６
倍の長寿命が得られた。Figure 2 shows the 600mm
These are the results of a 0 hour life test. In this life test, the device was operated at a high current density of 5 A/d. This figure shows the characteristics of the cathode of the present invention, in which a sintered layer is filled with an electron-emitting material in which 3% scandium oxide is dispersed. 4 is the conventional cathode shown in FIG. 5, in which 3% scandium oxide is dispersed in the electron emitting material layer; 4 shows the characteristics of the conventional oxide cathode shown in FIG. 3; As is clear from this figure, the characteristics of the electron tube cathode of the present invention were maintained at 80% of the initial value after 6000 hours, and in terms of life time, compared to the conventional cathode, the characteristics were maintained at 80% of the initial value.
A lifespan twice as long was obtained.
尚、実施例では、酸化スカンジウムの電子放射物質中へ
の分散量が３％のもので説明したが、分散量は０．１％
〜２０％の間であれば効果があった。In the example, the amount of dispersion of scandium oxide in the electron emitting material was 3%, but the amount of dispersion was 0.1%.
It was effective if it was between ~20%.
０．１％以下の場合は寿命特性の向上が得られず、又、
２０％以上にすると初期の電子放射特性が劣化した。If it is less than 0.1%, no improvement in life characteristics can be obtained;
When the amount exceeded 20%, the initial electron emission characteristics deteriorated.
この発明は以上も述べたように、少なくともシリコンを
還元性金属として含有する基体金属の上に、更に、シリ
コンを少なくとも還元性金属として含有する焼結金属層
を設け、この焼結層の中に酸化スカンジウムを分散させ
た電子放射物質を充填させた構成で、長時間（こ渡って
高電流密度動作させても寿命が長いという効果を奏する
。As described above, the present invention further provides a sintered metal layer containing at least silicon as a reducing metal on a base metal containing at least silicon as a reducing metal, and in this sintered layer. The structure is filled with an electron-emitting material in which scandium oxide is dispersed, and it has a long lifespan even when operated at high current density for long periods of time.
第１図はこの発明の電子管陰極の一実施例を示す概略断
面図、第２図は電子放射特性の比較図、第３図は酸化物
陰極の構成を説明するための概略断面図、第４図は酸化
物陰極の作用を説明するための部分拡大断面図、第５図
、第６図は従来の電子管陰極の一例を示す概略断面図で
ある。
図に於て、（１）は基体金属、（６）は焼結層、Ｑ５］
）はアルカリ土類金属酸化物、←４は酸化スカンジウム
、（５）は電子放射物質である。
なお、各図中、同一符号は同一または相当部分を示゛す
。FIG. 1 is a schematic sectional view showing one embodiment of an electron tube cathode of the present invention, FIG. 2 is a comparison diagram of electron emission characteristics, FIG. 3 is a schematic sectional view for explaining the structure of an oxide cathode, The figure is a partially enlarged sectional view for explaining the action of an oxide cathode, and FIGS. 5 and 6 are schematic sectional views showing an example of a conventional electron tube cathode. In the figure, (1) is the base metal, (6) is the sintered layer, Q5]
) is an alkaline earth metal oxide, ←4 is scandium oxide, and (5) is an electron emitting substance. In each figure, the same reference numerals indicate the same or corresponding parts.
Claims (1)
基体に、少なくともシリコンを含有し、主成分がニッケ
ルからなる粒子の焼結層を被着形成しこの焼結層の中に
バリウムを含むアルカリ土類金属酸化物と０．１〜２０
重量％の酸化スカンジウムを分散した電子放射物質を充
填したことを特徴とする電子管陰極。An alkaline earth metal whose main component is nickel and which forms a sintered layer of particles whose main component is nickel on a substrate which contains at least silicon and which contains barium in the sintered layer. Oxide and 0.1-20
An electron tube cathode characterized in that it is filled with an electron emitting material in which a weight percent of scandium oxide is dispersed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62300667A JPH01143116A (en) | 1987-11-27 | 1987-11-27 | Electronic tube cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62300667A JPH01143116A (en) | 1987-11-27 | 1987-11-27 | Electronic tube cathode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01143116A true JPH01143116A (en) | 1989-06-05 |
Family
ID=17887621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62300667A Pending JPH01143116A (en) | 1987-11-27 | 1987-11-27 | Electronic tube cathode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01143116A (en) |
-
1987
- 1987-11-27 JP JP62300667A patent/JPH01143116A/en active Pending
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