CN85104881A - Impregnated cathode - Google Patents
Impregnated cathode Download PDFInfo
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- CN85104881A CN85104881A CN 85104881 CN85104881A CN85104881A CN 85104881 A CN85104881 A CN 85104881A CN 85104881 CN85104881 CN 85104881 CN 85104881 A CN85104881 A CN 85104881A CN 85104881 A CN85104881 A CN 85104881A
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- Prior art keywords
- impregnated cathode
- thin layer
- oxide
- matrix
- emission
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Abstract
In heat-resisting porous matter matrix, immerse the impregnated cathode of electronic emission material, on the electronics surface of emission of this porous matter matrix, apply with thin layer.This thin layer is formed jointly by refractory metal and Sc (or oxide of Sc) or by the oxide of refractory metal and Sc and Sc, and the characteristics of this kind impregnated cathode just are this.Owing in matrix, immerse electronic emission material in advance, add the thin layer that has formed the oxide that contains Sc or Sc, so the monoatomic layer of being made up of Ba, Sc and O just is being able on the electronics surface of emission in the presence of the long-life ground.
Description
The present invention relates to a kind of impregnated cathode.Impregnated cathode one is to the negative electrode that is considered to keep for a long time high electron emissivity.But at reverse side, but exist the evaporation of working temperature height (about 1050～1200 ℃), electronic emission material barium big with high emission ability, the heater of heating usefulness bears problems such as incessantly long-time use.
In order to address this problem, proposed on the electronics surface of emission, to apply the scheme of this class noble metal of osmium, so just might make working temperature reduce about about 150 ℃.But, because by metallisation film and the basis material problem of counterdiffusion mutually, particularly under the situation of applying osmium, owing to the problem of oxidation, its effect is very unstable.
Replace applying the deposited film method of this metalloid of osmium, proposed impregnated cathode (Sc
2O
3The mixed matrix impregnated cathode) scheme is promptly used Sc
2O
3Or contain Sc oxide (for example (and Al, SC)
2) O
3) and thermal endurance metal such as tungsten form the matrix of agglomerated material, in this matrix, immerse electronic emission material (Japan Patent discloses clear 58-154131) then.
This negative electrode might reach lower working temperature than deposited osmium negative electrode.On the electronics surface of emission of this kind negative electrode, can form the monoatomic layer of forming by Ba, Sc and O, although this monoatomic layer of these characteristics is arranged owing in a single day any reason disappears with low work function.Just must adopt long-time high-temperature heat treatment to wait and make this monoatomic layer regeneration.And, also having the situation that regeneration is not come out, this is a problem from the life-span angle.
The object of the present invention is to provide a kind of like this impregnated cathode, it both can keep the characteristics of low-temperature working, can be easy to again replenish and the low work function monoatomic layer of regeneration.
Other purpose of the present invention is, in heat-resisting porous mass matrix, immerse in the prepared impregnated cathode of electronic emission material, on the electronics surface of emission of this porous mass matrix, apply skim again, this thin layer is by the oxide of refractory metal and Sc(or Sc), perhaps form the characteristics of Here it is impregnated cathode of the present invention jointly by the oxide of refractory metal and Sc and Sc.
Fig. 1 is the generalized section of an embodiment of impregnated cathode of the present invention, and Fig. 2 is the comparison diagram of the electron emission characteristic of negative electrode of the present invention and impregnated cathode in the past.
Above-mentioned Japan Patent is disclosed the electron emission face of the described negative electrode of clear 58-154131, and the element of measuring existing monoatomic layer with the surface analysis instrument forms, and has found out at Sc2O
3(or ScOX) upper absorption B is arrangedaComposition. Based on this result, the structure of negative electrode is wished the part and the additional Sc that replenish Ba2O
3The part branch come, and the passage of Ba is coupled together.
The method for making main points of impregnated cathode are: the hole part of the immersion tungsten porous heat-resistant matrixes such as electronic emission material barium aluminate. In order to make the barium aluminate melting, usually under the high temperature about 1700～1900 ℃, flood. If contain Sc at tungsten basal body this moment2O
3, then most of electronic emission material just at high temperature reacts, and variation becomes scandium acid barium (Ba3Sc
4O
9) etc., therefore, unreacted Sc2O
3(or ScOx) and Ba then form B at the electron emission facea, the monoatomic layer that forms of Sc and O, in camera tube and picture tube with this negative electrode, if cause Ions Bombardment because discharge waits, then may make this monoatomic layer disappearance. Make monoatomic layer regeneration, just must adopt high temperature to process for a long time, its reason is, in case formed Ba3Sc
4O
9Because it is high in conjunction with energy, vapour pressure is again low, make Ba3Sc
4O
9Produce decomposition reaction, and make the product after the decomposition spread, move to cathode surface, the processing procedure of overactivity energy will be arranged, therefore, be necessary that idea makes the formation of monoatomic layer without generating Ba3Sc
4O
9Process.
Therefore, the characteristics of negative electrode of the present invention are, give preparing the heat-resisting porous matter matrix that is impregnated with electronic emission material earlier, form refractory metal and S on the electronics surface of emission of this matrix
c(or S
cOxide) thin layer formed.
As heat-resisting porous matter matrix, can be according to the used matrix of former impregnated cathode.That is to say available following material: W, M
C, I
r, P
t, R
eDeng simple substance or its alloy, its porosity can be 12～50%, and comparatively ideal is 15～35%, and optimal is 20～25%.In addition, well-known, in porous matter matrix, can add z
r, H
f, Ti, C
r, H
n, A
l, S
iOne or two or more kinds activator Deng element as interpolation.Also can adopt the matrix that is added with this Class Activation agent in the present invention.
The thickness of thin layer is that 10nm～1 μ m is comparatively desirable.Can be from refractory metal W, M
O, I
r, O
S, R
eAnd P
tDeng in select a kind of metal at least and make thin layer.S
c(or) S
C2O
3The general 1-20%(percentage by weight of content) comparatively desirable, 5～15%(percentage by weight preferably), if Sc or S
C2O
3Content less, then working temperature just can not reduce.In addition, because of S
C2O
3Be electrical insulator, its content too much also is unfavorable.The porosity of this thin layer is comparatively desirable less than 20%, less than 10% just better, even the available any method of thin layer obtains, normally applies with vacuum sputtering, also has dusty material to burn the seal method, and all methods of utilizing agglomerated material to apply all can be used.
Below, with Fig. 1 one embodiment of the present of invention are described.Fig. 1 is the generalized section of impregnated cathode of the present invention.1 is sheet of cathode material (φ 1.4) among the figure, and it is that 20～25% porous matter tungsten basal body 2 and hole 3 form by porosity, and porous matter matrix can be used MO, I
r, P
t, R
eDeng or their alloy make.Immerse electronic emission material B in the hole 3
aC
O3, C
aC
O3, Al
2O
3, they are that 4: 1: 1 ratio cooperates with mole ratio.In addition, the also material of available other mole ratio or be added with the electronic emission material of other material, this cathode sheets is loaded on T
aCup 4. in, T then
a Cup 4 usefulness laser welding are in Ta sleeve 5.If without laser welding, then available scolder welding, negative electrode is heated by heater 7, and heater 7 is the tungsten core silks 6 that apply aluminium oxide.Above-mentioned electronic emission material is as B
aSupply source, the increment of Ba is relevant with heating-up temperature, also can be by changing the mole ratio of electronic emission material, also can be by Zr, the H that contains in the basis material
f, T
i, C
r, M
n, S
i, A
lRegulate Sc Deng activator
2O
3Supply source be to be tungsten and the Sc of 10nm～1 μ m by thickness
2O
3The film of forming 8.This film forms with the high-frequency sputtering coating.Also available M
O, R
e, P
t, Z
r, T
aReplace tungsten on metal or they alloy.
In the K-A diode mode that constitutes with such negative electrode, adding pulsewidth on anode is that 5 μ S, repetition rate are the high-voltage pulse of 100HZ, and has measured saturation current density, and its result as shown in Figure 2.
Figure has 9 to be to be covered with tungsten and Sc according to the present invention
2O
3The characteristic of the negative electrode of film.The Sc in past
2O
3The characteristic of mixed matrix impregnated cathode is consistent with characteristic 9 of the present invention.But, if at A
rAmbient pressure about 5 * 10
-5Holder is down carried out A with the emission current of 25ma
rIon sputtering 5 minutes, then B
a, S
cThe monoatomic layer of forming with O will be removed, and its characteristic becomes characteristic 10, on the contrary, though negative electrode of the present invention is through A
rIon sputtering, but the deterioration phenomenon of electron emission characteristic does not appear.
According to the present invention, even owing to any reason, the monoatomic layer that Ba, Sc and O form has also disappeared, but because these elements in the work can be replenished, so can not occur the phenomenon that emission characteristics descends fully. In addition, even characteristic is utilized 1150 ℃ just in case decline is arranged, the heat treatment about 15～30 minutes also can form completely monoatomic layer, thereby can keep the characteristics of long-life, low-temperature working.
Claims (4)
1, in heat-resisting porous matter matrix, immerses the impregnated cathode of electronic emission material, it is characterized in that, on the electronics surface of emission of this porous matter matrix, apply with thin layer.This thin layer is by refractory metal and S
c(or S
cOxide), perhaps by refractory metal and S
cAnd S
cOxide form jointly.
2, impregnated cathode according to claim 1, the thickness of its above-mentioned thin layer are 10nm～1 μ m.
3, impregnated cathode according to claim 1, in its above-mentioned thin layer, S
cAnd S
cThe content of oxide be 1～20%(percentage by weight).
4, impregnated cathode according to claim 1, its above-mentioned refractory metal can be from W, M
o, I
r, O
S, Re and P
tA kind of Deng selecting at least in the metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN85104881A CN85104881B (en) | 1985-06-26 | 1985-06-26 | Impregnated cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN85104881A CN85104881B (en) | 1985-06-26 | 1985-06-26 | Impregnated cathode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN85104881A true CN85104881A (en) | 1987-01-07 |
| CN85104881B CN85104881B (en) | 1988-12-21 |
Family
ID=4794120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN85104881A Expired CN85104881B (en) | 1985-06-26 | 1985-06-26 | Impregnated cathode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN85104881B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100461327C (en) * | 2004-12-30 | 2009-02-11 | 中国科学院电子学研究所 | Method for preparing metal nanometer thin film dipped barium-tungsten cathode |
| CN108878232A (en) * | 2018-07-04 | 2018-11-23 | 中国科学院电子学研究所 | Hot cathode component for vacuum electron device |
-
1985
- 1985-06-26 CN CN85104881A patent/CN85104881B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100461327C (en) * | 2004-12-30 | 2009-02-11 | 中国科学院电子学研究所 | Method for preparing metal nanometer thin film dipped barium-tungsten cathode |
| CN108878232A (en) * | 2018-07-04 | 2018-11-23 | 中国科学院电子学研究所 | Hot cathode component for vacuum electron device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN85104881B (en) | 1988-12-21 |
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| C13 | Decision | ||
| GR02 | Examined patent application | ||
| C14 | Grant of patent or utility model | ||
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