JPH04115437A - Oxide cathode - Google Patents
Oxide cathodeInfo
- Publication number
- JPH04115437A JPH04115437A JP2234783A JP23478390A JPH04115437A JP H04115437 A JPH04115437 A JP H04115437A JP 2234783 A JP2234783 A JP 2234783A JP 23478390 A JP23478390 A JP 23478390A JP H04115437 A JPH04115437 A JP H04115437A
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- oxide layer
- cathode
- scandium
- alkaline earth
- 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
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 11
- 239000002184 metal Substances 0.000 claims abstract description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052706 scandium Inorganic materials 0.000 claims abstract description 10
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910052788 barium Inorganic materials 0.000 claims description 8
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 8
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 5
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 4
- 239000010953 base metal Substances 0.000 claims description 3
- HYXGAEYDKFCVMU-UHFFFAOYSA-N scandium oxide Chemical compound O=[Sc]O[Sc]=O HYXGAEYDKFCVMU-UHFFFAOYSA-N 0.000 abstract description 9
- 238000006243 chemical reaction Methods 0.000 abstract description 3
- 230000002542 deteriorative effect Effects 0.000 abstract description 3
- 239000000758 substrate Substances 0.000 description 14
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 6
- 229910052791 calcium Inorganic materials 0.000 description 6
- 239000011575 calcium Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 229910052712 strontium Inorganic materials 0.000 description 5
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 4
- 239000011777 magnesium Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- 239000000020 Nitrocellulose Substances 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 229920001220 nitrocellulos Polymers 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- -1 alkaline earth metal carbonate Chemical class 0.000 description 1
- CSDREXVUYHZDNP-UHFFFAOYSA-N alumanylidynesilicon Chemical compound [Al].[Si] CSDREXVUYHZDNP-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- JUVGUSVNTPYZJL-UHFFFAOYSA-N chromium zirconium Chemical compound [Cr].[Zr] JUVGUSVNTPYZJL-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 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〕
本発明は酸化物陰極に関し、特に陰極線管などに用いら
れる長寿命酸化物陰極に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oxide cathode, and particularly to a long-life oxide cathode used in cathode ray tubes and the like.
今日、陰極線管や蛍光表示管の熱電子源とじて酸化物陰
極が広く使用されている。Today, oxide cathodes are widely used as thermionic sources for cathode ray tubes and fluorescent display tubes.
第２図は従来の陰極線管に使われている酸化物陰極を示
すものであり、陰極基体１は、０００１〜数十重量％の
マグネシウム、シリコンアルミニウム、タングステン、
ジルコニウム クロムなどの還元性金属を含み主成分が
ニッケルであるカップ状の基体金属から成り、陰極基体
１の表面には、少なくともバリウムを含み、その他とし
てストロチウム若しくはカルシウム又はその両者を含む
アルカリ土類金属酸化物層２を被着し、陰極基体１の内
側にはヒータ３が設けられ、約８００℃まで加熱して陰
極表面から熱電子を取り出す構造になっている。FIG. 2 shows an oxide cathode used in a conventional cathode ray tube, and the cathode substrate 1 is composed of magnesium, silicon aluminum, tungsten, 0001 to several tens of weight percent.
It consists of a cup-shaped base metal that contains a reducing metal such as zirconium chromium and whose main component is nickel, and the surface of the cathode base 1 is made of an alkaline earth metal that contains at least barium and in addition strotium or calcium or both. An oxide layer 2 is deposited on the cathode substrate 1, and a heater 3 is provided inside the cathode substrate 1 to heat the cathode to about 800° C. and extract thermoelectrons from the cathode surface.
一般に、酸化物陰極は、次のような手順により製造され
る。Generally, an oxide cathode is manufactured by the following procedure.
（１）まず、第２図で示すように、カップ状の陰極基体
１上にニトロセルロースを接着剤としてアルカリ土類金
属炭酸塩を被覆する。(1) First, as shown in FIG. 2, a cup-shaped cathode substrate 1 is coated with an alkaline earth metal carbonate using nitrocellulose as an adhesive.
（２）シかる後に、真空中でヒータ３により加熱して炭
酸塩（ＢａＣＯ３で代表〉を酸化物に変換する。(2) After heating, the carbonate (representatively represented by BaCO3) is converted into an oxide by heating with a heater 3 in a vacuum.
ＢａＣＯ３−ＢａＯ＋Ｃ○２
（３）次に、アルカリ土類金属酸化物層２と陰極基体１
中に含有せしめた還元性金属（Ｍｇで代表）とを反応さ
せて酸化物中に遊離Ｂａを形成する。BaCO3-BaO+C○2 (3) Next, alkaline earth metal oxide layer 2 and cathode substrate 1
Free Ba is formed in the oxide by reacting with a reducing metal (typically Mg) contained therein.
ＢａＯ＋Ｍｇ −ＭｇＯ＋Ｂａ
このように形成された遊ＭＢａが、アルカリ土類金属酸
化物層２中の活性中心として働き、陰極表面の仕事関数
を下げ電子が放射されるようになる。BaO+Mg -MgO+Ba The free MBa thus formed acts as an active center in the alkaline earth metal oxide layer 2, lowering the work function of the cathode surface and allowing electrons to be emitted.
上述した従来の酸化物陰極では、以下に説明する理由の
ためＩＡ／ｃｍ２以上の電子放射密度を取り出すことが
できない。With the conventional oxide cathode described above, it is not possible to extract an electron emission density of IA/cm2 or more for the reasons explained below.
陰極基体１とアルカリ土類金属酸化物層２との間にアル
カリ土類金属酸化物が還元される反応の過程でできる還
元性金属の酸化物、例えば、ＭｇＯ，５ｉ０２及びアル
カリ土類金属酸化物とが結合し、電気抵抗が高く、かつ
、陰極基体１中の還元性金属の拡散を妨げる中間層がで
きる。この中間層は、電気抵抗が窩いために高い電流密
度を陰極から取り出そうとするとジュール熱が発生する
ため、中間層の生成が早まり陰極の寿命をさらに短くす
るとともに、ジュール熱が上がり過ぎた場合には陰極の
破壊に至ることもある。Oxides of reducing metals formed in the process of the reaction in which the alkaline earth metal oxide is reduced between the cathode substrate 1 and the alkaline earth metal oxide layer 2, such as MgO, 5i02 and alkaline earth metal oxides. are combined to form an intermediate layer that has high electrical resistance and prevents the diffusion of the reducing metal in the cathode substrate 1. This intermediate layer has a low electrical resistance and generates Joule heat when trying to extract a high current density from the cathode, which accelerates the formation of the intermediate layer and further shortens the life of the cathode. may lead to destruction of the cathode.
このような要求に対して、例えば、特開昭６１２７１７
３２号公報には電子管陰極のアルカリ土類金属酸化物層
に酸化スカンジウムの粉末を分散して含有させたものが
開示されている。アルカリ土類金属酸化物層中の酸化ス
カンジウムは、酸化物層の導電率を高め、かつ、中間層
の導電率を高める効果がある。In response to such requests, for example, Japanese Patent Application Laid-Open No. 612717
No. 32 discloses an electron tube cathode in which scandium oxide powder is dispersed and contained in an alkaline earth metal oxide layer. Scandium oxide in the alkaline earth metal oxide layer has the effect of increasing the electrical conductivity of the oxide layer and of the intermediate layer.
アルカリ土類金属酸化物中に酸化スカンジウムを分散さ
せた酸化物陰極は、中間層の導電率を高くする効果はあ
るが、初期電子放出特性が酸化スカンジウムを分散させ
ないものに較べて悪く、長時間のエージング時間が必要
であること、さらに、電子放出が不均一であると等の欠
点があった。An oxide cathode in which scandium oxide is dispersed in an alkaline earth metal oxide has the effect of increasing the conductivity of the intermediate layer, but its initial electron emission characteristics are poorer than those in which scandium oxide is not dispersed, and it cannot be used for a long time. This method has drawbacks such as requiring a long aging time and non-uniform electron emission.
本発明の目的は、中間層の導電率を高くするとともに初
期電子放出特性、均一な電子放出特性を得ることができ
る酸化物陰極を提供することにある。An object of the present invention is to provide an oxide cathode in which the conductivity of the intermediate layer is increased and initial electron emission characteristics and uniform electron emission characteristics can be obtained.
Ｃ課題を解決するための手段〕
本発明の酸化物陰極は、還元性金属を含み主成分がニッ
ケルである基体金属上にスカンジウムと少くともバリウ
ムを含むアルカリ土類金属との酸化物から成る第１酸化
物層を被覆し、該第１酸化物層上にスカンジウムを含ま
ないアルカリ土類金属酸化物から成る第２酸化物層が被
覆されている。Means for Solving Problem C] The oxide cathode of the present invention comprises an oxide of scandium and an alkaline earth metal containing at least barium on a base metal containing a reducing metal and having nickel as its main component. A second oxide layer comprising a scandium-free alkaline earth metal oxide is coated on the first oxide layer.
次に、本発明の実施例について図面を参照して説明する
。Next, embodiments of the present invention will be described with reference to the drawings.
第１図は本発明の一実施例の断面図である。FIG. 1 is a sectional view of one embodiment of the present invention.
第１図に示すように、陰極基体１は、０．００１〜数十
重量％のマグネシウム、シリコン７アルミニウム、タン
グステン、ジルコニウム、クロムなどの還元性金属を含
み主成分がニッケルであるカップ状の基体金属から成り
、陰極基体１の表面には０．１〜２０重量％の酸化スカ
ンジウムを含み、その他バリウム、ストロンチウム、カ
ルシウムの酸化物から成る第１酸化物層１２が被覆され
、さらに、第１酸化物層１２の上には、バリウム、スト
ロンチウム、カルシウムのいわゆるアルカリ土類金属酸
化物から成る第２酸化物層１３が被覆され、陰極基体１
の内側にはヒータ３が設けられて陰極基体１．第１酸化
物層１２及び第２酸化物層１３を加熱し、陰極表面から
熱電子を取り出す構造となっている。As shown in FIG. 1, the cathode substrate 1 is a cup-shaped substrate containing 0.001 to several tens of weight percent of reducing metals such as magnesium, silicon 7 aluminum, tungsten, zirconium, and chromium, and whose main component is nickel. The surface of the cathode substrate 1 is made of metal and is coated with a first oxide layer 12 containing 0.1 to 20% by weight of scandium oxide and also containing oxides of barium, strontium, and calcium. A second oxide layer 13 made of so-called alkaline earth metal oxides such as barium, strontium, and calcium is coated on the cathode substrate 12.
A heater 3 is provided inside the cathode substrate 1. The structure is such that the first oxide layer 12 and the second oxide layer 13 are heated to extract thermoelectrons from the cathode surface.
この陰極の２層構造の酸化物層は、まず、最初に、第１
酸化物層１２に含まれるスカンジウム。The two-layer oxide layer of this cathode is first
Scandium contained in the oxide layer 12.
バリウム、ストロンチウム、カルシウムの複合炭酸塩を
被覆し、その後、第２酸化物層１３に含まれるバリウム
、ストロンチウム、カルシウムの複合炭酸塩を被覆して
真空中でヒータ３により炭酸塩を加熱２分解して得るこ
とができる。A composite carbonate of barium, strontium, and calcium is coated, and then a composite carbonate of barium, strontium, and calcium contained in the second oxide layer 13 is coated, and the carbonate is heated and decomposed by a heater 3 in a vacuum. You can get it.
このような２層の酸化物層を有する構造においては、陰
極基体１と第１酸化物層１２との間に陰極基体１中の還
元性金属と第１酸化物層１２との還元反応の際に生しる
中間層が生成されるが、スカンジウムか介在するなめに
その電気抵抗値が小さく、高い電流密度をこの陰極から
取り出した場合でもジュール熱の発生を低く抑えること
ができる。In such a structure having two oxide layers, there is a gap between the cathode substrate 1 and the first oxide layer 12 during the reduction reaction between the reducing metal in the cathode substrate 1 and the first oxide layer 12. An intermediate layer is formed, but due to the presence of scandium, its electrical resistance is low, and even when a high current density is extracted from this cathode, the generation of Joule heat can be suppressed to a low level.
また、第２酸化物層１３には酸化スカンジウムが含まれ
ていないため、スカンジウム酸化物に特有の初期放出電
流特性を劣化させることもなく均一な電子放圧を得るこ
とができる。Further, since the second oxide layer 13 does not contain scandium oxide, uniform electron discharge pressure can be obtained without deteriorating the initial emission current characteristics peculiar to scandium oxide.
本実施例においては、第１酸化物層１２としてスカンジ
ウム及びその他のアルカリ土類金属との炭酸塩を用いた
が、酸化スカンジウムとその他のバリウム、ストロンチ
ウム、カルシウムの炭酸塩とをニトロセルロースを加え
て十分に混合したものを使用しても同様の効果を得るこ
とができる。In this example, carbonates of scandium and other alkaline earth metals were used as the first oxide layer 12, but scandium oxide and other carbonates of barium, strontium, and calcium were combined with nitrocellulose. A similar effect can be obtained by using a sufficiently mixed mixture.
以上説明したように本発明の酸化物陰極は、酸化物層を
スカンジウムを含む第１酸化物層とスカンジウムを含ま
ない第２酸化物層の２層構造とし、第１酸化物層と陰極
基体中に含まれる還元性金属層との還元反応により生成
する中間層の電気抵抗を低減することにより、ジュール
熱の発生を抑えることができるため、高電流密度を取る
ことができるとともに長寿命を得ることかでき、かつ、
第２酸化物層にはスカンジウムが含まれていないため初
期放出電流を劣化させることなく均一な放出電流を従来
と同等な短時間で得ることができるという効果がある。As explained above, the oxide cathode of the present invention has a two-layer structure in which the oxide layer is a first oxide layer containing scandium and a second oxide layer not containing scandium. By reducing the electrical resistance of the intermediate layer generated by the reduction reaction with the reducing metal layer contained in the material, the generation of Joule heat can be suppressed, making it possible to obtain high current density and long life. Can be done, and
Since the second oxide layer does not contain scandium, it has the effect that a uniform emission current can be obtained in a short time comparable to the conventional method without deteriorating the initial emission current.
第１図は本発明の一実施例の断面図、第２図は従来の陰
極線管の酸化物陰極の一例の断面図である。
１・・・陰極基体、２・・・酸化物層、３・・・ヒータ
、１２・・・第１酸化物層、１３・・・第２酸化物層。FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of an example of an oxide cathode of a conventional cathode ray tube. DESCRIPTION OF SYMBOLS 1... Cathode base body, 2... Oxide layer, 3... Heater, 12... First oxide layer, 13... Second oxide layer.
Claims (1)
スカンジウムと少くともバリウムを含むアルカリ土類金
属との酸化物から成る第１酸化物層を被覆し、該第１酸
化物層上にスカンジウムを含まないアルカリ土類金属酸
化物から成る第２酸化物層を被覆したことを特徴とする
酸化物陰極。A first oxide layer consisting of an oxide of scandium and an alkaline earth metal containing at least barium is coated on a base metal containing a reducing metal and mainly composed of nickel, and scandium is coated on the first oxide layer. An oxide cathode characterized in that it is coated with a second oxide layer made of an alkaline earth metal oxide that does not contain.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2234783A JPH04115437A (en) | 1990-09-05 | 1990-09-05 | Oxide cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2234783A JPH04115437A (en) | 1990-09-05 | 1990-09-05 | Oxide cathode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04115437A true JPH04115437A (en) | 1992-04-16 |
Family
ID=16976309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2234783A Pending JPH04115437A (en) | 1990-09-05 | 1990-09-05 | Oxide cathode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04115437A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105244244A (en) * | 2015-10-13 | 2016-01-13 | 甘肃虹光电子有限责任公司 | Oxide cathode |
-
1990
- 1990-09-05 JP JP2234783A patent/JPH04115437A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105244244A (en) * | 2015-10-13 | 2016-01-13 | 甘肃虹光电子有限责任公司 | Oxide cathode |
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