JPH0118537B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to electron emitting electronics, and more particularly to cathodes for gas discharge tubes. The present invention provides a flash gas discharge tube for a gas discharge device such as a flash valve, a gas discharge lightning arrester,
It can also be used in electronic tubes, etc. Tungsten cathodes coated with a cesium film are conventionally known (e.g. Dobretsov LN,
Gomoiunova MVEmission Electronics,
Moscow, Nauka Publ., 1966, p. 195). This cathode has a relatively high work function, and the cathode temperature
It is about 1.36eV at 600℃, so the emission power is rather low, and at this temperature 0.1m
Do not exceed A/ ^cm2 . Moreover, the electron emission properties of this cathode are not sufficiently stable during operation, especially under strong ion bombardment, which destroys the cesium film on its surface under the conditions mentioned above. gas discharge tube,
In particular, flash gas discharge tubes have too high a discharge starting voltage and have a short lifespan. Even more difficult is that it is extremely difficult to measure cesium deposited on the surface of the cathode in the process of manufacturing the cathode. It is necessary to measure cesium accurately.
This is because the amount of cesium on the cathode surface determines the electron emission ability of the cathode. The technical complexity of measuring cesium precludes the use of such cathodes in gas discharge tubes and electronic vacuum tubes. The cathode is manufactured as a sintered body, which is much simpler to manufacture. Among such known cathodes, a cathode using a cesium compound as an electron emitting material has the highest emission ability. A gas discharge tube having such a cathode has a low discharge starting voltage. As is known in the art, the cathode comprises a refractory metal such as molybdenum, tungsten, tantalum, niobium or mixtures thereof as refractory metal, and also gas absorbing metals and additives to improve the firing process. The cathode is made as a sintered body and a layer of an electron-emitting substance such as cesium carbonate or cesium chromate is deposited on the sintered body (West German Patent Application No. 3002033 C1.HOIJ61/
06 Published on July 24, 1980). The gas-absorbing metal is titanium, zirconium, vanadium, hafnium or mixtures thereof. Additives that improve the sintering process are aluminum or silicon oxides. The discharge starting voltage of a gas discharge tube with the above cathode is
150-190V, varies depending on the composition of the sintered body,
After 10,000 flashes, the discharge start voltage is 155
~200V, and virtually no sputtering of the cathode material occurs (see the above-mentioned West German patent application). As is known, cathodes are made of refractory metals or mixtures containing such metals and sintered bodies containing electron-emitting metals (for example, West German Patent Application No. 3008518 Class HOIJ61/
06, released on September 11, 1980). In this cathode, the electron-emitting substance contained in the sintered body is a substance containing biomium ions, and the other electron-emitting substance is Cs ₂ MO ₄ dispersed within the pores of the sintered body, and M is a fire-resistant material. indicates a metal. The refractory metals are usually heavy transition metals belonging to groups 1, 2 or 3 of the periodic table, such as zirconium, tungsten, tantalum or molybdenum. In the prior art, gas discharge tubes are filled with ionized gas and have two electrodes spaced apart within the tube. One of these electrodes is a cathode, which is made from the cathode described above (see the above-mentioned West German patent application). This discharge tube has an inner diameter of 5 mm, and the cathode is 37 mm from the anode.
is seperated. Filled with xenon to a pressure of 125mmHg,
This discharge tube has a pulse discharge starting voltage of 4.5KV, a discharge voltage of 190V, and a pulse discharge starting voltage of 9.0KV.
It is 132V. In other discharge tubes, the similar distance between poles is 20mm,
The inner diameter is 2.5mm, it is filled with xenon at a pressure of 520mmHg, the flash energy is 11.5J, the pulse discharge starting voltage is 3.3KV, and the discharge starting voltage is 176V. In this case, the discharge voltage remained at the initial voltage after 1500 flashes. During the discharge operation of this cathode, the cesium compound reacts with the metal forming part of the sintered body.
As a result, free cesium is produced, reducing the work function of the cathode and thus increasing its emissive capacity. During the operating process, cesium is continuously evaporated from the cathode surface, which is more intense during ion bombardment. The evaporated cesium is replenished by cesium atoms coming from the cathode body as a result of the above reaction. The amount of cesium in the cathode thus gradually decreases, and the emission capacity of the cathode decreases accordingly.
It also increases the firing voltage of gas discharge tubes using this cathode, thereby shortening the life of the discharge tube. An object of the present invention is to provide a cathode that stably maintains a high emission capacity during long-term operation. An advantage of the present invention is that, in a gas discharge tube using the above-mentioned cathode, the discharge starting voltage is stable and low discharge voltage is provided during long-term operation. The cathode of the present invention is a cathode made of a sintered body containing a refractory metal or a mixture thereof and an electron-emitting substance containing an aluminosilicate of cesium or rubidium. The sintered body contains 0.5-25% by weight of aluminosilicate of cesium or rubidium, and the remainder is a refractory metal or a mixture thereof, which contributes to sufficiently high emission capacity of the cathode and allows strong ion bombardment. It can operate stably for a long period of time even under low conditions. In order to achieve high radioactivity, it is desirable that the cesium or rubidium aluminosilicate has the following composition: _{xM2O.yAl2O3.zSiO2} In _the formula, M is Cs or Rb, x= _1-3 , y ₌ 1-2, z=1-6. Furthermore, in order to maximize the emission capacity of the cathode, the sintered body contains 85% by weight of nickel and 15% by weight of cesium aluminosilicate, and the following salt composition is advantageous. Cs ₂ O Al ₂ O ₃ 2SiO ₂ In order to enhance the emission of the cathode, which also contains inexpensive electron-emitting materials, the sintered body contains 85% by weight of nickel and 15% by weight of rubidium aluminosilicate; The following composition is convenient. Rb ₂ O Al ₂ O ₃ 2SiO ₂ Also, in order to increase the emission performance of the cathode used in powerful gas discharge tubes, the sintered body contains 90% by weight of tantalum.
10% by weight of cesium aluminosilicate, and the salt preferably has the following composition. Cs ₂ O Al ₂ O ₃ 2SiO ₂ In order to increase the emissivity of the cathode to withstand ion bombardment, the sintered body contains 90% by weight of a 1:1 mixture of zirconium-niobium and 10% by weight of cesium aluminosilicate. The following composition of salt is recommended: Cs ₂ O Al ₂ O ₃ 2SiO ₂ The present invention also provides a gas discharge tube filled with an ionized gas and having two spaced apart electrodes within the tube. One of the electrodes is a cathode, which is made up of the cathode described above. The cathode of the present invention can maintain stable and high emission performance even under strong ion bombardment over a long period of time. A gas discharge tube using such a cathode has the advantage of being able to maintain a stable and low discharge starting voltage over a long period of time, and of being small in size. The invention will be illustrated in more detail with reference to the accompanying drawings, in which: FIG. The cathode 1 (FIG. 1) of the present invention is a sintered body containing a refractory metal or a mixture thereof and an electron-emitting substance. The refractory metal referred to here is one of the following metals: nickel (melting point = 1728K);
Zirconium (T=2128K), Hafnium (T=
2250K), tantalum (T=3270K), niobium (T=
2770K), rhenium (T=3308K), molybdenum (T=2890K), tungsten (T=3650K) or a mixture thereof. Electron-emissive materials include cesium or rubidium aluminosilicates. The sintered body of the cathode 1 contains 0.5 to 25% by weight of cesium or rubidium aluminosilicate, the remainder being a refractory metal or a mixture thereof. This component ratio can provide the cathode with high emission performance. If the cesium or rubidium aluminosilicate content is less than 0.5% by weight,
The collected emission current cannot exceed the order of 1/1000 μA/cm ² . Such compounds are clearly of no practical use. If the cesium or rubidium aluminosilicate content exceeds 25% by weight, the collected emission current will be several tens of mA/
cm ² , but the components of the sintered body cannot form an alloy, so the cathode as a whole cannot be practically used. Cesium or rubidium aluminosilicates have the following composition: xM ₂ O・yAl ₂ O ₃・zSiO _2In the formula, M is Cs or Rb, x=1 to 3, y
=1-2, z=1-6. The emission current collected from cathode 1 is a function of the particular values of x, y and z. To illustrate this, the following table shows the electron emission properties of cesium aluminosilicate.

[Table] Rubidium aluminosilicate has very similar electron emission values, with a slightly lower collected emission current. Therefore, when the x, y, and z values of the aluminosilicate are within the above ranges, rubidium aluminosilicate can be used as the electron-emitting substance. Aluminosilicates of other compositions have low electron emissive activity and are therefore not suitable for use as emissive materials. The cathode properties are not only a function of the composition of the electron-emitting material, but also depend on the chemical properties of the refractory metal contained in the sintered body. The following metals, Ni, Zr, Hf, Ta, Nb, Re, Mo
and W are divided into three groups. The most active metals are Ni, Zr and Hf, followed by
Ta, Nb and Re, and finally Mo and W. As a result, it is also advantageous for the cathode 1 to have a sintered body containing a metal selected from the group of nickel.
This is superior to the cathode 1 having a sintered body containing a metal selected from the tantalum group. However, a selection from the tantalum group is more effective than a cathode having a sintered body containing a metal selected from the molybdenum group. The sintered body contains 85% by weight of nickel and 15% by weight of cesium aluminosilicate, and the salt composition is
A cathode made of a sintered body of Cs ₂ O Al ₂ O ₃ 2SiO ₂ has a high emission ability. Contains 85% by weight of nickel and 15% by weight of rubidium aluminosilicate, with a salt composition of Rb ₂ O.
A cathode made of a sintered body of Al ₂ O ₃ 2SiO ₂ has a rather high emission capacity. Although the cathode 1 comprising rubidium aluminosilicate has inferior emission performance than the cathode 1 comprising cesium aluminosilicate, rubidium is preferred over cesium in some cases because it is a cheaper and more readily available material. The cathode 1 whose sintered body contains nickel can be advantageously used in gas discharge tubes whose emission current does not exceed 800 A. If the emission current is higher than this, the nickel will spatter rapidly. The cathode for high-power gas discharge tubes should be a sintered body containing a metal selected from the group of tantalum or molybdenum, whose melting point is much higher than that of nickel. In such a cathode, 90% by weight of tantalum
and 10% by weight of cesium aluminosilicate, and the cathode 1 is made of a sintered body having a salt composition of Cs ₂ O Al ₂ O ₃ 2SiO ₂ and has a high emission ability. The sintered body of the cathode 1 may include a mixture of refractory metals in which the alloy formed by these metals has an equal weight ratio of metal atoms. The efficiency of the cathode depends on the most active metal in the mixture. Such a cathode can therefore have a high emission power approximately equal to that of an effective nickel-containing cathode. It has at the same time resistance to strong ion bombardment. For this purpose, the sintered body should contain a mixture of metals selected from the group of nickel, which metals have a higher melting point than nickel-zirconium or hafnium, for example metals selected from the group of tantalum or molybdenum. A mixture is preferred. The most preferred of these is that the sintered body contains 90% by weight of a mixture of zirconium and niobium in a weight ratio of 1:1 and 10% by weight of cesium aluminosilicate, and the salt composition is Cs ₂ O. _{Al2O32SiO2 _ _}
This is a sintered body cathode. This cathode has a high emissivity and is more resistant to ion bombardment than a sintered cathode containing nickel. Furthermore, since the zirconium-niobium mixture has greater plasticity than nickel, the cathode can be easily manufactured. The cathode 1 (FIG. 2) according to the invention can be advantageously used in a gas discharge tube, which is filled with an ionized gas, for example xenon, and has two electrodes spaced apart within the tube 2. That is, a cathode 1 and an anode 3 are arranged. The cathode 1 is attached to a support 4. The outer surface of the tube 2 is covered with a transparent conductor (not shown). A special example of this discharge tube is a flash gas discharge tube. However, cathodes can be used in gas discharge arresters and vacuum electron tubes. The cathode of the present invention can be manufactured in any size and shape. For example, as shown in FIGS. 1 and 2, the refractory metal or mixture thereof and the electron-emissive material are formed into the shape of a disc, rod or sphere, although they can be cylindrical, and are formed by known compression molding methods. is shaped and sintered in a vacuum or in a protective atmosphere. This compression molding varies depending on the composition of the mixture, but generally does not exceed 10 T/cm ² . The sintering temperature varies between 1000 and 2000 K depending on the components of the mixture. Next, examples will be shown for better understanding of the present invention. Example 1 Cathode 1 (Figure 1) was made of 99.5% by weight Ni and Cs ₂ O.
It is a sintered body containing 0.5% by weight of Al ₂ O ₃ 2SiO ₂ and is manufactured as follows. Powdered nickel and cesium aluminosilicate had the above compositions and were mixed in the above weight ratio. The compression molded body was fired at a temperature of 1000K for 10 minutes in a vacuum with a pressure of about 10 ^-4 mmHg. The emission current of cathode 1 produced in this way is 0.6m.
At A/cm ² , the effective work function was 0.89 eV.
The measurement was carried out in a vacuum with a pressure of 10 ^-8 to ^{10 -9} mmHg, the cathode temperature was room temperature (300K), and the electric field strength E = 2 ×
Measured as 10 ⁴ V/cm. The effective cathode work function was the electron emission constant A=120 A/cm ² ·degr ² of the Richardson-Dushman equation. This emission parameter remained virtually unchanged even when the cathode temperature reached 700K. The cathode 1 has a sintered body having a different composition,
The compression pressure, firing temperature and period were different from the above method. Example 2 The cathode 1, which is a sintered body containing 85% by weight of Ni and 15% by weight of Cs ₂ O Al ₂ O ₃ 2SiO ₂ , was manufactured in the same manner as in Example 1. Here, the compression pressure was 5T/cm ² , the firing temperature was 1300K, and the firing was continued for 30 minutes. The cathode 1 manufactured as described above has an emission current of
101.6mA/ ^cm2 , effective work function =
It was 0.67eV. The measurement conditions were the same as in Example 1. Example 3 A cathode 1 of a sintered body containing 85% by weight of Ni and 15% by weight of Rb ₂ O Al ₂ O ₃ 2SiO ₂ was manufactured in the same manner as in Example 1. Firing pressure is 5T/cm ² and firing temperature is 1300K.
Lasted 25 minutes. The cathode 1 manufactured in this way has an emission current of 76.5 m
It was A/ ^cm2 . Its effective work function = 0.72eV
The measurement conditions were the same as in Example 1. Example 4 Cathode 1 contains 75% by weight of Zr and Rb ₂ O Al ₂ O ₃ SiO ₂ 25
% by weight, and was produced in the same manner as in Example 1. Compression pressure is 7T/cm ² and firing temperature
1500K was maintained for 50 minutes. The cathode produced in this way has an emission current of 4 m
The measurement conditions were the same as in Example ¹ . Example 5 90% by weight of Hf and 10 _% by weight of 3Rb ₂ O 2Al ₂ O ₃ 6SiO 2
A sintered body cathode 1 containing the following was produced in the same manner as in Example 1. Compression pressure is 6T/cm ² and firing temperature is 1200K.
lasted for 20 minutes. The cathode manufactured as described above has an emission current of 6.9 mA/cm ² at room temperature, and the electric field strength E
= 1.5×10 ⁴ V/cm. Example 6 The cathode 1, which is a sintered body containing 99.5% by weight of a mixture of Zr and Hf in a weight ratio of 1: ₂ and 0.5% by weight of Rb ₂ O.Al ₂ O ₃ .2SiO 2 , was prepared in the same manner as in Example 1. Manufactured by The compression pressure was 3T/ ^cm2 , and the sintering temperature was 1000K.
Connected for minutes. The cathode had an emission current of 0.2 mA/cm ² and the measurement conditions were the same as in Example 1. Example 7 Cathode 1, which is a sintered body containing 99.5% by weight of Nb _{and 0.5} % by weight of Cs ₂ O.Al ₂ O 3 .2SiO 2 , was produced in the same manner as in Example 1. Compression pressure is 4T/ ^cm2 and sintering temperature
1100K was maintained for 8 minutes. The emission current of the cathode was 0.2 mA/cm ² , and the measurement conditions were the same as in Example 1. Example 8 Ta 90% by weight and Cs ₂ O・Al ₂ O ₃・2SiO ₂ 10% by weight
The cathode 1, which is a sintered body containing the following, was manufactured in the same manner as in Example 1. The compression pressure is 6T/ ^cm2 , and the firing temperature is
1300K was maintained for 10 minutes. The emission current of the cathode was 30.5 mA/cm ² , the effective work function was 0.75 eV, and the measurement conditions were the same as in Example 1. Example 9 The cathode 1, which is a sintered body containing 90% by weight of Re and 10% by weight of 2Rb ₂ O.Al ₂ O ₃ .5SiO ₂ , was produced in the same manner as in Example 1. The compression pressure was 6T/cm ² and the firing temperature was 1300K for 10 minutes. The emission current of the cathode was 7.2 mA/cm ² , and the measurement conditions were the same as in Example 1. Example 10 90% by weight mixture of Ta and Re in a weight ratio of 1:1
A cathode 1, which is a sintered body containing 10% by weight of 2Cs ₂ O Al ₂ O ₃ 5SiO _{2 ,} was produced in the same manner as in Example 1.
The compression pressure was 6T/cm ² and the firing temperature was 1300K for 10 minutes. The emission current of the cathode is determined by the electric field strength E=1.5×10 ⁴ V/
cm at room temperature was 9.3 mA/cm ² . Example 11 Cathode 1, which is a sintered body containing 90% by weight of a mixture containing Zr and Nb at a weight ratio of 1:1 and 10% by weight of Cs ₂ O Al ₂ O ₃ 2SiO ₂ , was prepared in the same manner as in Example 1. Manufactured. The compression pressure was 5T/ ^cm2 , and the firing temperature was 1300K.
Lasted for minutes. The emission current of the cathode was 80 mA/cm ² , the effective work function was 0.71 eV, and the measurement conditions were the same as in Example 1. Example 12 A cathode 1 made of a sintered body containing 90% by weight of Mo and 10% by weight of 3Cs ₂ O Al ₂ O ₃ 6SiO ₂ was manufactured as follows. 85.5% by weight of powdered molybdenum, 9.5% by weight of cesium aluminosilicate having the above composition, and 5% by weight of polyvinyl alcohol were mixed. Polyvinyl alcohol is a plasticizer to facilitate compaction and firing. After crushing this mixture, pressure
Compressed at 8T/ ^cm2 . Then vacuum 10 ^-4 mmHg, 1400K
The compressed body was fired for 15 minutes. The emission current of the cathode is determined by the electric field strength E=1.5×10 ⁴ V/
cm at room temperature was 0.31 mA/cm ² . Example 13 W70% by weight and 2Cs ₂ O 2Al ₂ O ₃ 5SiO ₂ 25% by weight
A sintered body cathode 1 containing the following was manufactured as follows. A mixture was prepared containing 71.25% by weight tungten, 23.75% by weight cesium aluminosilicate and 5% by weight polyvinyl alcohol. This mixture was compressed at a pressure of 10 T/cm ² and then vacuumed at 10 ^-4 mmHg.
The firing temperature was maintained at 1800K for 20 minutes. The emission current of the cathode was 0.11 mA/cm ² , and the measurement conditions were the same as in Example 12. Example 14 90% by weight mixture of Mo and Ta in a weight ratio of 1:2
A cathode 1 of a sintered body containing 10% by weight of Cs ₂ O Al ₂ O ₃ SiO ₂ was produced in the same manner as in Example 1. The compression pressure is
A firing temperature of 1300K was maintained for 10 minutes at 6T/cm ² . The emission current of the cathode was 17.7 mA/cm ² , and the measurement conditions were the same as in Example 1. Example 15 90% by weight mixture of Hf and Mo in a weight ratio of 1:2
A cathode 1, which is a sintered body containing 10% by weight of 2Rb ₂ O 2Al ₂ O ₃ 5SiO _{2 ,} was produced in the same manner as in Example 1.
The compression pressure was 5T/cm ² and the firing temperature was 1300K for 20 minutes. The emission current of the cathode was 4.5 mA/cm ² , and the measurement conditions were the same as in Example 12. A cathode prepared similarly to Example 2 is useful for use in the gas discharge tube of FIG. 2, particularly in a flash bulb. However, the gas discharge tube of the present invention could usefully use any of the above cathodes. A gas discharge tube using cathode 1 was operated as follows. The gas in tube 2 was previously ionized in a known manner. A firing pulse of sufficient voltage to specifically ionize the gas was applied to the transparent conductive coating of the tube. Further, a voltage consisting of a pulse having an amplitude equal to or exceeding the discharge starting voltage was applied to the cathode 1 and the anode 3. The applied voltage caused electrons to be emitted from the cathode, causing a discharge between the electrodes, resulting in a strong luminescent emission, or flash. In this proposed discharge tube, the discharge starting voltage and its operating voltage were varied along with the work function of the cathode of the present invention. As a result, the smaller the work function of the cathode, the lower the electrical characteristics of the discharge tube. As the firing voltage and operating voltage of the discharge tube decrease, the thermal load on the cathode decreases during operation. In summary, the electrical characteristics of a gas discharge tube depend on the working function of the cathode used within the tube. In the above examples, the cathode of the present invention had a work function lower than 1 eV at the room temperature of the cathode, and had high radioactivity. This means that electron-emitting materials containing cesium or rubidium aluminosilicates are approximately
It has a low work function of 1 eV, due to the presence of ions of alkali metals, namely cesium or rubidium. These ions are uniformly distributed in interstitial positions in the crystal lattice of the aluminosilicate and are held in place by electrostatic forces. There is little evaporation of alkali metals, ie cesium or rubidium, from the cathode;
It contributes to stabilizing the emission characteristics of the cathode over a long period of time and generally extends the life of gas discharge tubes using such a cathode. A special embodiment of the gas discharge tube according to the invention is a pulsed gas discharge tube for a flash valve with a flash energy of 15 J. This discharge tube has an inner diameter of 2 mm. The distance between cathode 1 and anode 3 is 16
mm, this tube is filled with ionized xenon at a pressure of 600 mmHg. Cathode 1 was manufactured in the same manner as in Example 2, and its outer diameter was 1.5 mm. The discharge tube had a discharge starting voltage of 180V, a discharge starting pulse voltage of 4.5KV, an operating voltage of 200V, and a discharge current of 500A. After 40,000 flashes these properties remained virtually unchanged. Another embodiment of the discharge tube is a pulsed gas discharge tube with a flash energy of 40 J. This discharge tube had an inner diameter of 3.2 mm, the distance between the cathode 1 and the anode 3 was 30 mm, and was filled with ionized gas, ie, xenon, at a pressure of 230 to 250 mmHg. Cathode 1 was manufactured in the same manner as in Example 2, and had an outer diameter of 2.4 mm. This discharge tube had a discharge starting voltage of 80V, a discharge starting pulse voltage of 4.5KV, an operating voltage of 110V, and a discharge current of 500A. After 40,000 flashes, these characteristic values remained virtually unchanged. The advantage of the cathode of the invention is its very low working function, which was =0.6-0.9 eV at room temperature. This increases the electric field strength to 2×10 ⁴ V/cm
It was possible to collect up to 100 mA/cm ² of current emitted from the cathode. Another advantage of this cathode is that it is extremely resistant to ion bombardment. For example, when this cathode is used in a gas discharge tube, even if the ionized gas pressure is as high as about 600 mmHg, its emission capacity remains unchanged from its initial value even after 40,000 flashes. Deterioration of the cathode was only noticed after 65,000 flashes. Of particular note is that the sintered body of this cathode contains 85-90% nickel, a metal that is easily sputtered for use in the sintered cathode.
Other high melting point metals such as tantalum, tungsten, etc., when used in the composition of the sintered body of the cathode, greatly increase the resistance of this cathode to ion bombardment. The above benefits of cathode are when used in gas discharge tubes.
Operation specific values can be kept high. For example, it emits a large amount of light, has a low gas discharge starting voltage, is small in size, and has a long life. For example, the pulsed gas discharge tube of the present invention has a flash energy of 15J,
The discharge starting voltage is 180V, and the diameter of the light emitting part 2 is
It is 15mm and has a lifespan of over 40,000 flashes.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the cathode of the present invention, and the second
1 is a longitudinal sectional view of a gas discharge tube according to the invention having a cathode according to FIG. 1; FIG. 1... cathode, 2... tube, 3... anode, 4... support.

Claims (1)

[Claims] 1. A cathode made of a sintered body containing a resistance-resistant metal or a mixture thereof and an electron-emitting material, wherein the electron-emitting material contains an aluminosilicate of cesium or rubidium. Characteristic cathodes for gas discharge tubes. 2. The cathode according to claim 1, wherein the sintered body contains 0.5 to 25% by weight of an aluminosilicate of cesium or rubidium, and the remainder is a refractory metal or a mixture thereof. 3 Cesium or rubicium aluminosilicate has the formula xM ₂ O・yAl ₂ O ₃・zSiO ₂ (where M is Cs or Rb, x=1-3, y=1-2, z=1-6 Claim 1 having the composition represented by
Or the cathode described in item 2. 4. Claim 3, wherein the sintered body contains 85% by weight of nickel and 15% by weight of cesium aluminosilicate, and the composition of this salt corresponds to the formula Cs ₂ O.Al _{2 O} 3.2SiO ₂ Cathode as described in section. 5 The sintered body contains 85% by weight of nickel and rubidium aluminosilicate, and the composition of this salt corresponds to the formula Rb ₂ O.Al _{2 O} 3.2SiO ₂ cathode. 6 Claim 3, wherein the sintered body contains 90% by weight of tantalum and 10% by weight of cesium aluminosilicate, and the composition of this salt corresponds to the formula Cs ₂ O.Al _{2 O} 3.2SiO ₂ Cathode as described in section. 7 The weight ratio of zirconium to niobium in the sintered body is 1:
1 mixture 90% by weight and cesium aluminosilicate
10% by weight, and the composition of this salt corresponds to the formula Cs ₂ O.Al _{2 O} 3.2SiO ₂ .