US3578834A - Generation of alkali metals - Google Patents

Generation of alkali metals Download PDF

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US3578834A
US3578834A US798785A US3578834DA US3578834A US 3578834 A US3578834 A US 3578834A US 798785 A US798785 A US 798785A US 3578834D A US3578834D A US 3578834DA US 3578834 A US3578834 A US 3578834A
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alkali metal
zirconium
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chromate
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Paolo Della Porta
Elio Rabusin
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/22—Means for obtaining or maintaining the desired pressure within the tube
    • H01J17/26—Means for producing, introducing, or replenishing gas or vapour during operation of the tube
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
    • H01J5/08—Vessels; Containers; Shields associated therewith; Vacuum locks provided with coatings on the walls thereof; Selection of materials for the coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
    • H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
    • H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering

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  • Murphy ABSTRACT Compositions of matter which release alkali metal vapors comprising an alkali metal compound and a reducing agent for the compound wherein the reducing agent is an alloy of 5 to 30 weight percent aluminum balance zirconium. These compositions are useful in processes for the release of alkali metal vapors used in the production of photosensitive surfaces in vacuum tubes.
  • alkali metals such as cesium, potassium and/or sodium
  • the alkali metals are employed to produce photosensitive surfaces such as those in television pickup tubes, photo multiplier tubes, electronic sights, image conversion tubes, and image intensifier tubes for radiological uses.
  • the alkali metal is commonly introduced into such tubes by means of an alkali metal vapor dispenser containing a compound of the desired alkali metal and a reducing agent for the compound.
  • an alkali metal vapor dispenser containing a compound of the desired alkali metal and a reducing agent for the compound.
  • Such a dispenser employing silicon as a reducing agent for cesium chromate is described in Eichenbaum et al. Cesium Vapor Dispenser," The Review of Scientific Instruments, Vol. 35, No. 6, June 1964, pp. 691-693.
  • Such dispensers are also described by Lester US.
  • Another object is to provide compositions which release a substantially pure alkali metal vapor free of noxious gases such as oxygen.
  • a further object is to provide novel alkali metal releasing compounds employing a zirconium-aluminum alloy as the reducing agent wherein the alloy has advantages not realized by mixtures of the same metals.
  • composite structures which comprise a sintered matrix of a sinterizable material such as iron and within the matrix and alkali metal chromate and a zirconium-aluminum alloy as a reducing agent for the chromate. While such composite structures are effective for the purpose described, i.e., reduction ofundesirable loose particles it has been discovered that the heating necessary to sinter the sinterizable material alters the composite structure in some unknown manner such that when the alkali metal vapor is later released it is contaminated with large quantities of noxious gases.
  • Zirconium-aluminum alloys of differing particle sizes have been employed as described in U.S. Pat. No. 3,385,644 admixed with mercuric oxide but have not heretofore been employed with alkali metal compounds as in the present invention.
  • Ad additional advantage of the compositions of the present invention is that the zirconium-aluminum alloy need not be used in differing particle sizes.
  • the alkali metal compound can be any compound which is reducible to its metal by a reducing agent and is sufficiently stable alone and in admixture with its reducing agent to withstand the heat treatments commonly employed in the outgasing of vacuum tubes.
  • the preferred alkali metal compounds are those which are stable at temperatures up to 400 C.
  • suitable alkali metal compounds include among others cesium chloride, sodium dichromate and most preferably cesium chromate, potassium chromate, sodium chromate, rubidium chromate and lithium chromate.
  • chromates are greatly preferred over the dichromates because of the reduced amount of oxygen which they release.
  • the reducing agents employed in the present invention are zirconium-aluminum alloys and generally those of 5 to 30 weight percent aluminum balance zirconium, preferably those of 13 to 18 weight percent aluminum, balance zirconium and especially those of 16 percent aluminum and 84 percent zirconium produced as described in US. Pat. No. 3,203,901. It will be understood that minor amounts of other common impurities and compatible metals can be included in the alloy provided they do not materially affect the novel characteristics of the composition.
  • the alkali metal compound and the zirconium-aluminum alloy are both preferably employed as finely divided particles and generally those which pass through a screen of mesh per inch and preferably those which pass through a screen of 270 mesh per inch.
  • the iron or other sinterizable material when present also has these particle sizes.
  • the alkali metal compound and zirconium-aluminum alloy can be mixed in widely varying ratios but a stoichiometric excess of the zirconium-aluminum alloy is generally employed in order to completely reduce the reducible alkali metal com- .
  • a process for releasing an alkali metal vapor in a vacuum The composition of alkali metal compound and zirconium-aluminum alloy is placed in any metallic container capable of withstanding elevated temperatures. This container is then placed in a vacuum tube which is then evacuated mechanically or by any other suitable means while being maintained at 350 to 400 C. for l to 8 hours while evacuating residual gases. The container is thenheated to the temperature of the onset of the reaction between the alloy and the alkali metal compound and generally between 450 and 1000 C. and preferably between 550 and 900 C. for a time sufficient to completely or partially reduce the alkali metal compound releasing the desired amount of'alkali metal vapor.
  • EXAMPLE 1 This example illustrates the small amount of gas released when cesium chromate is reduced with an alloy of 16 percent aluminum and 84 percent zirconium.
  • EXAMPLE 2 This comparative example illustrates the large amount of gas released by cesium chromate reduced with a mixture of one part by weight of aluminum and eight parts by weight of zirconium following the teaching of Lester supra.
  • example 1 The above procedure of example 1 is repeated employing the same times, temperatures. conditions and ingredients except that the zirconium-aluminum alloy is replaced by an equal weight ofa mixture of one part by weight aluminum and eight parts by weight zirconium.
  • the quantity of gas released is to be found to be 12 cc.-torr/mg. or approximately 40 times the amount of gas released in example I wherein the preferred zirconium-aluminum alloy is employed as the reducing agent.
  • EXAMPLE 3 The procedure of example 1 is repeated twice employing the same times, temperatures. components and conditions the first time with the exception that the cesium chromate is replaced by a stoichiometrically equivalent amount of sodium chromate and the second time with the exception that the cesium chromate is replaced by a stoichiometrically equivalent amount of potassium chromate. Similar results are obtained with low quantities of gas being evolved with the sodium or potassium vapor.
  • cc-torr refers to the volume of gas in cubic centimeters at a pressure of one torr (1 mm. Hg. absolute) and is independent of the pressure. As can be seen by comparing example 1 and 2 the compositions of Lester release 40 times the amount of undesirable gas released by the compositions of the present invention.
  • a composition of matter useful for generating an alkali metal in a vacuum consisting of an alkali metal compound which is reducible to its metal and which is stable up to 400 C and a zirconium-aluminum alloy as a reducing agent for the alkali metal compound wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal compound are present in a weight ratio of 1:1 to 20:1.
  • composition of claim 1 wherein the compound of the alkali metal is an alkali metal chromate.
  • a composition of claim 1 wherein the compound of the alkali metal is selected from the group consisting of cesium chromate, potassium chromate and sodium chromate.
  • a composition of claim 1 wherein the zirconium-aluminum alloy contains l6 percent aluminum and 84 percent zirconium.
  • composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting of:
  • composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting essentially of:
  • composition of matter useful for generating an alkali metal vapor in a vacuum consisting essentially of an alkali metal chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the alloy and the chromate are both finely divided such that they pass through a U.S. standard screen of at least mesh per inch.
  • a composition of matter useful for generating an alkali metal vapor in a vacuum consisting essentially of cesium chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the chromate are both finely divided such that they pass through a U.S. standard screen of at least 100 mesh per inch.
  • a composition of matter useful for generating an alkali metal in a vacuum comprising an alkali metal compound which is reducible to its metal and which is stable up to 400 C and a zirconium-aluminum alloy as a reducing agent for the alkali metal compound wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal compound are present in a weight ratio of 1:1 to 20:1.
  • a composition ofclaim 10 wherein the compound of the alkali metal is an alkali metal chromate.
  • a composition of claim 10 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
  • composition of matter for releasing an alkali metal vapor, in a vacuum comprising:
  • a process for releasing an alkali metal in a vacuum tube comprising heating to a temperature sufficient to release an alkali metal, a finely divided mixture consisting essentially of an alkali metal chromate which is stable up to 400 C. and a zirconium-aluminum alloy wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal chromate are present in a weight ratio of 1:1 to 20:1.
  • a process of claim 15 for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of:
  • a process for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of:

Abstract

Compositions of matter which release alkali metal vapors comprising an alkali metal compound and a reducing agent for the compound wherein the reducing agent is an alloy of 5 to 30 weight percent aluminum balance zirconium. These compositions are useful in processes for the release of alkali metal vapors used in the production of photosensitive surfaces in vacuum tubes.

Description

United States Patent [72] inventors Paolo Della Porta;
Elio Rabusin, Milan, Italy [21] Appl. No. 798,785
[22] Filed Feb. 12,1969
[45] Patented May 18, 1971 [73] Assignee S.A.E.S. Getters S.p.A.
Milan, Italy [32] Priority Dec. 13, 1966, Oct. 12, 1967 [3 3 Italy [3 1 1 31040/66 and 21538A/67 Pat. 784903 Continuation-impart of application Ser. No. 690,125, Dec. 13, 1967.
[54] GENERATION OF ALKALI METALS 20 Claims, No Drawings [52] U.S.Cl 316/16, 252/18l.4, 252/l8l.6
[51] Int.Cl H0lj9/38, l-lOlj 7/12 [50] FieldofSearch. 252/l81.4, 181.1,l8l.3,18l.6,l81.7;3l6/16 [5 6] References Cited UNITED STATES PATENTS 2,117,735 5/1938 Lester 252/18l.4X 3,385,644 5/1968 DellaPortaetal. 316/16 Primary Examiner-Tobias E. Levow Assistant ExaminerJ. Cooper Attorney-David R. Murphy ABSTRACT: Compositions of matter which release alkali metal vapors comprising an alkali metal compound and a reducing agent for the compound wherein the reducing agent is an alloy of 5 to 30 weight percent aluminum balance zirconium. These compositions are useful in processes for the release of alkali metal vapors used in the production of photosensitive surfaces in vacuum tubes.
GENERATION OF ALKALI METALS CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of parent application Ser. No. 690,125 filed Dec. 13, 1967 entitled Metal Vapor Generators.
It is frequently desirable to provide electron tubes containing alkali metals such as cesium, potassium and/or sodium. For example, the alkali metals are employed to produce photosensitive surfaces such as those in television pickup tubes, photo multiplier tubes, electronic sights, image conversion tubes, and image intensifier tubes for radiological uses. The alkali metal is commonly introduced into such tubes by means of an alkali metal vapor dispenser containing a compound of the desired alkali metal and a reducing agent for the compound. Such a dispenser employing silicon as a reducing agent for cesium chromate is described in Eichenbaum et al. Cesium Vapor Dispenser," The Review of Scientific Instruments, Vol. 35, No. 6, June 1964, pp. 691-693. Such dispensers are also described by Lester US. Pat. No. 2,117,735 (1938) who employs a mixture of cesium chromates as the alkali metal compound and as the reducing agent a mixture of zirconium powder and aluminum powder in a weight ratio of 8:1. Unfortunately, the alkali metal vapor releasing compositions of Eichenbaum and Lester and other prior compositions release an alkali metal vapor contaminated with noxious gases such as oxygen. These gases react with the alkali metal and reduce the photosensitivity of the resulting surface.
Accordingly. it is an object of the present invention to provide novel alkali metal vapor releasing compositions which are substantially free of one or more disadvantages of prior compositions.
Another object is to provide compositions which release a substantially pure alkali metal vapor free of noxious gases such as oxygen.
A further object is to provide novel alkali metal releasing compounds employing a zirconium-aluminum alloy as the reducing agent wherein the alloy has advantages not realized by mixtures of the same metals.
Additional objects and advantages of the present invention will be apparent by the following detailed description thereof.
In the parent application composite structures are described which comprise a sintered matrix of a sinterizable material such as iron and within the matrix and alkali metal chromate and a zirconium-aluminum alloy as a reducing agent for the chromate. While such composite structures are effective for the purpose described, i.e., reduction ofundesirable loose particles it has been discovered that the heating necessary to sinter the sinterizable material alters the composite structure in some unknown manner such that when the alkali metal vapor is later released it is contaminated with large quantities of noxious gases. in accordance with the present invention it has been discovered that compositions having no sinterized material and therefore those which consist essentially of an alkali metal compound and a zirconium-aluminum alloy release an alkali metal vapor which is substantially free of noxious gases. Zirconium-aluminum alloys of differing particle sizes have been employed as described in U.S. Pat. No. 3,385,644 admixed with mercuric oxide but have not heretofore been employed with alkali metal compounds as in the present invention. Ad additional advantage of the compositions of the present invention is that the zirconium-aluminum alloy need not be used in differing particle sizes.
The alkali metal compound can be any compound which is reducible to its metal by a reducing agent and is sufficiently stable alone and in admixture with its reducing agent to withstand the heat treatments commonly employed in the outgasing of vacuum tubes. Thus the preferred alkali metal compounds are those which are stable at temperatures up to 400 C. Examples of suitable alkali metal compounds include among others cesium chloride, sodium dichromate and most preferably cesium chromate, potassium chromate, sodium chromate, rubidium chromate and lithium chromate. The
chromates are greatly preferred over the dichromates because of the reduced amount of oxygen which they release.
The reducing agents employed in the present invention are zirconium-aluminum alloys and generally those of 5 to 30 weight percent aluminum balance zirconium, preferably those of 13 to 18 weight percent aluminum, balance zirconium and especially those of 16 percent aluminum and 84 percent zirconium produced as described in US. Pat. No. 3,203,901. It will be understood that minor amounts of other common impurities and compatible metals can be included in the alloy provided they do not materially affect the novel characteristics of the composition.
The alkali metal compound and the zirconium-aluminum alloy are both preferably employed as finely divided particles and generally those which pass through a screen of mesh per inch and preferably those which pass through a screen of 270 mesh per inch. The iron or other sinterizable material when present also has these particle sizes.
The alkali metal compound and zirconium-aluminum alloy can be mixed in widely varying ratios but a stoichiometric excess of the zirconium-aluminum alloy is generally employed in order to completely reduce the reducible alkali metal com- .pound and generally in ratios of 1:1 to 20:1 and preferably 3:1 to 10:1 parts by weight of alloy per part by weight of reducible compound.
According to another inseparableaspect of the present invention there is provided a process for releasing an alkali metal vapor in a vacuum. The composition of alkali metal compound and zirconium-aluminum alloy is placed in any metallic container capable of withstanding elevated temperatures. This container is then placed in a vacuum tube which is then evacuated mechanically or by any other suitable means while being maintained at 350 to 400 C. for l to 8 hours while evacuating residual gases. The container is thenheated to the temperature of the onset of the reaction between the alloy and the alkali metal compound and generally between 450 and 1000 C. and preferably between 550 and 900 C. for a time sufficient to completely or partially reduce the alkali metal compound releasing the desired amount of'alkali metal vapor.
The invention is further illustrated by the following examples in which all parts and percentages are by weight unless otherwise indicated. These nonlimiting examples are illustrative of certain embodiments and are designed to teach those skilled in the art how to practice the invention and to represent the best mode presently known for carrying out the invention.
EXAMPLE 1 This example illustrates the small amount of gas released when cesium chromate is reduced with an alloy of 16 percent aluminum and 84 percent zirconium.
Into a mortar is placed 500 grams of a zirconium-aluminum alloy commercially available as Stl0l from S.A.E.S. Getters S.p.A. containing 16 percent aluminum and 84 percent zirconium. This alloy is ground with a pestle until it is a fine powder which passes through a screen of 270 mesh/inch, whereupon it is mixed with 100 grams of cesium chromate which has been similarly ground. A portion of this mixture is placed in a container of Nichrome V having a slit therein. The container is then placed in a vacuum tube and the entire assembly heated in a vacuum of 10' torr for 8 hours at 375 C. to remove residual gases. The assembly is cooled and then the container alone is heated to 600 C. whereupon cesium begins to evaporate. The temperature is increased in steps of 8 C/minute up to a maximum temperature of 850 C. This temperature is maintained for 1 minute. The cesium vapor deposits on the cold walls of the tube. During the period of cesium vapor release the tube is connected to a vacuum pump via a conduit containing a conductance which acts as a gas flow restricting orifice. The pressure on each side of the orifice is continuously recorded during the period of cesium vapor release and the total quantity of gases released calculated according to the following formula:
wherein:
Q the quantity of gas in cc.-torr c conductance of the orifice 146 cc./sec.)
P,, pressure upstream of the conductance in torr Pp pressure downstream of the conductance in torr t time at onset of cesium vapor release t time at completion of cesium vapor release in seconds dt incremental time in seconds The quantity of gas is found to be 0.3 cc.-torr/mg. of cesium chromate.
EXAMPLE 2 This comparative example illustrates the large amount of gas released by cesium chromate reduced with a mixture of one part by weight of aluminum and eight parts by weight of zirconium following the teaching of Lester supra.
The above procedure of example 1 is repeated employing the same times, temperatures. conditions and ingredients except that the zirconium-aluminum alloy is replaced by an equal weight ofa mixture of one part by weight aluminum and eight parts by weight zirconium. The quantity of gas released is to be found to be 12 cc.-torr/mg. or approximately 40 times the amount of gas released in example I wherein the preferred zirconium-aluminum alloy is employed as the reducing agent.
EXAMPLE 3 The procedure of example 1 is repeated twice employing the same times, temperatures. components and conditions the first time with the exception that the cesium chromate is replaced by a stoichiometrically equivalent amount of sodium chromate and the second time with the exception that the cesium chromate is replaced by a stoichiometrically equivalent amount of potassium chromate. Similar results are obtained with low quantities of gas being evolved with the sodium or potassium vapor.
As used herein the term cc-torr" refers to the volume of gas in cubic centimeters at a pressure of one torr (1 mm. Hg. absolute) and is independent of the pressure. As can be seen by comparing example 1 and 2 the compositions of Lester release 40 times the amount of undesirable gas released by the compositions of the present invention.
Although the invention has been described in considerable detail with reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described above and as defined in the appended claims.
We claim:
1. A composition of matter useful for generating an alkali metal in a vacuum, said composition of matter consisting of an alkali metal compound which is reducible to its metal and which is stable up to 400 C and a zirconium-aluminum alloy as a reducing agent for the alkali metal compound wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal compound are present in a weight ratio of 1:1 to 20:1.
2. A composition of claim 1 wherein the compound of the alkali metal is an alkali metal chromate.
3. A composition of claim 1 wherein the compound of the alkali metal is selected from the group consisting of cesium chromate, potassium chromate and sodium chromate.
4. A composition of claim 1 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
5. A composition of claim 1 wherein the zirconium-aluminum alloy contains l6 percent aluminum and 84 percent zirconium.
6. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting of:
a. an alkali metal chromate and b. an alloy of 5 to 30 weight percent aluminum balance zirconium present in excess of stoichiometry.
7. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting essentially of:
a. an alkali metal chromate and b. an alloy of 13 to 18 weight percent aluminum, balance zirconium present in excess of stoichiometry.
8. A composition of matter useful for generating an alkali metal vapor in a vacuum, said composition consisting essentially of an alkali metal chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the alloy and the chromate are both finely divided such that they pass through a U.S. standard screen of at least mesh per inch.
9. A composition of matter useful for generating an alkali metal vapor in a vacuum, said composition consisting essentially of cesium chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the chromate are both finely divided such that they pass through a U.S. standard screen of at least 100 mesh per inch.
10. A composition of matter useful for generating an alkali metal in a vacuum, said composition of matter comprising an alkali metal compound which is reducible to its metal and which is stable up to 400 C and a zirconium-aluminum alloy as a reducing agent for the alkali metal compound wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal compound are present in a weight ratio of 1:1 to 20:1.
11. A composition ofclaim 10 wherein the compound of the alkali metal is an alkali metal chromate.
12. A composition of claim 10 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
13. A composition of claim 10 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
14. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition comprising:
a. an alkali metal chromate and b. an alloy of 5 to 30 weight percent aluminum balance zirconium present in excess of stoichiometry.
15. A process for releasing an alkali metal in a vacuum tube comprising heating to a temperature sufficient to release an alkali metal, a finely divided mixture consisting essentially of an alkali metal chromate which is stable up to 400 C. and a zirconium-aluminum alloy wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal chromate are present in a weight ratio of 1:1 to 20:1.
16. The process of claim 15 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
17. The process of claim 15 wherein the zirconium-aluminum alloy contains 13 to 18 weight percent aluminum balance zirconium.
18. The process of claim 17 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
19. A process of claim 15 for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of:
l. introducing into the tube a composition of matter of an alkali metal chromate and an alloy of 13 to 18 weight percent zirconium, balance aluminum present in excess of stoichiometry;
11. closing the tube and connecting it to a vacuum pump;
Ill. heating the tube at 300 to 400 C for l to 8 hours while evacuating residual gases; and
IV. heating the composition of matter at 550 to 900 C. to
release the alkali metal vapor.
20. A process for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of:
l. introducing into the tube a composition of matter of an alkali metal chromate and an alloy of 5 to 30 weight percent zirconium. balance aluminum wherein the alloy and Ill. heating the tube to evacuate residual gases; and IV. heating the composition of matter to release the alkali metal vapor.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3.578 .834 Dated -?Y 9 a Paolo della Porta. Elia Rabuqin It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 63, "Ad" should be "An" -6 Column 2, line 65, "10 should be "10 Signed and sealed this 28th day of September 1971.
(SEAL) Attest:
ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.
Acting Commissioner of Patents Attesting Officer FORM PC4050 (lo'sg) uscoMM-Dc 00376-F'69 U 5, GOVERNMENT PRTYTING OFFICE 959 0-35613

Claims (19)

  1. 2. A composition of claim 1 wherein the compound of the alkali metal is an alkali metal chromate.
  2. 3. A composition of claim 1 wherein the compound of the alkali metal is selected from the group consisting of cesium chromate, potassium chromate and sodium chromate.
  3. 4. A composition of claim 1 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
  4. 5. A composition of claim 1 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
  5. 6. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting of: a. an alkali metal chromate and b. an alloy of 5 to 30 weight percent aluminum balance zirconium present in excess of stoichiometry.
  6. 7. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition consisting essentially of: a. an alkali metal chromate and b. an alloy of 13 to 18 weight percent aluminum, balance zirconium present in excess of stoichiometry.
  7. 8. A composition of matter useful for generating an alkali metal vapor in a vacuum, said composition consisting essentially of an alkali metal chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the alloy and the chromate are both finely divided such that they pass through a U.S. standard screen of at least 100 mesh per inch.
  8. 9. A composition of matter useful for generating an alkali metal vapor in a vacuum, said composition consisting essentially of cesium chromate and an alloy of 16 percent aluminum and 84 percent zirconium wherein the weight ratio of alloy to chromate is from 3:1 to 10:1 and wherein the chromate are both finely divided such that they pass through a U.S. standard screen of at least 100 mesh per inch.
  9. 10. A composition of matter useful for generating an alkali metal in a vacuum, said composition of matter comprising an alkali metal compound which is reducible to its metal and which is stable up to 400* C and a zirconium-aluminum alloy as a reducing agent for the alkali metal compound wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal compound are present in a weight ratio of 1:1 to 20:1.
  10. 11. A composition of claim 10 wherein the compound of the alkali metal is an alkali metal chromate.
  11. 12. A composition of claim 10 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
  12. 13. A composition of claim 10 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
  13. 14. A composition of matter for releasing an alkali metal vapor, in a vacuum said composition comprising: a. an alkali metal chromate and b. an alloy of 5 to 30 weight percent aluminum balance zirconium present in excess of stoichiometry.
  14. 15. A process for releasing an alkali metal in a vacuum tube comprising heating to a temperature sufficient to release an alkali metal, a finely divided mixture consisting essentially of an alkali metal chromate which is stable up to 400* C. and a zirconium-aluminum alloy wherein the zirconium-aluminum alloy contains 5 to 30 weight percent aluminum balance zirconium wherein the alloy and the alkali metal chromate are present in a weight ratio of 1:1 to 20:1.
  15. 16. The process of claim 15 wherein the zirconium-aluminum alloy is present in excess of stoichiometry.
  16. 17. The process of claim 15 wherein the zirconium-aluminum alloy contains 13 to 18 weight percent aluminum balance zirconium.
  17. 18. The process of claim 17 wherein the zirconium-aluminum alloy contains 16 percent aluminum and 84 percent zirconium.
  18. 19. A process of claim 15 for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of: I. introducing into the tube a composition of matter of an alkali metal chromate and an alloy of 13 to 18 weight percent zirconium, balance aluminum present in excess of stoichiometry; II. closing the tube and connecting it to a vacuum pump; III. heating the tube at 300* to 400* C for 1 to 8 hours while evacuating residual gases; and IV. heating the composition of matter at 550* to 900* C. to release the alkali metal vapor.
  19. 20. A process for releasing an alkali metal vapor in a vacuum tube comprising in sequence the steps of: I. introducing into the tube a composition of matter of an alkali metal chromate and an alloy of 5 to 30 weight percent zirconium, balance aluminum wherein the alloy and the alkali metal chromate are present in a weight ratio of 1:1 to 20:1; II. closing and evacuating the tube; III. heating the tube to evacuate residual gases; and IV. heating the composition of matter to release the alkali metal vapor.
US798785A 1966-12-13 1969-02-12 Generation of alkali metals Expired - Lifetime US3578834A (en)

Applications Claiming Priority (2)

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IT3104066 1966-12-13
IT2153867 1967-10-12

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Cited By (16)

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Publication number Priority date Publication date Assignee Title
US4099079A (en) * 1975-10-30 1978-07-04 U.S. Philips Corporation Secondary-emissive layers
US4459949A (en) * 1982-02-12 1984-07-17 Teves-Thompson Gmbh Liquid metal cooled internal combustion engine valves with getter
US4988318A (en) * 1983-03-10 1991-01-29 Gte Products Corporation Unsaturated vapor high pressure sodium lamp arc tube fabrication process
WO2002093664A2 (en) * 2001-05-15 2002-11-21 Saes Getters S.P.A Cesium dispensers and process for the use thereof
US20050145179A1 (en) * 2002-09-06 2005-07-07 Saes Getters S.P.A. Accessory member for dispensers of alkali metals
WO2006027814A2 (en) * 2004-09-10 2006-03-16 Saes Getters S.P.A. Mixtures for evaporation of lithium and lithium dispensers
AT501721B1 (en) * 2005-03-11 2006-11-15 Konstantin Technologies Ges M EVAPORATOR SOURCE FOR EVAPORATING ALKALI / ERDALKALIMETALLEN
US20060257296A1 (en) * 2005-05-13 2006-11-16 Sarnoff Corporation Alkali metal dispensers and uses for same
US20090266201A1 (en) * 2006-03-13 2009-10-29 Saes Getters S.P.A. Use of Magnesium-Copper Compositions for the Evaporation of Magnesium and Magnesium Dispensers
US7842194B2 (en) 2004-11-24 2010-11-30 Saes Getters S.P.A. Dispensing system for alkali metals capable of releasing a high quantity of metals
CN103906854A (en) * 2011-11-11 2014-07-02 工程吸气公司 Organic-inorganic composition for the vapour release of alkali or alkali-earth metals
US10545461B1 (en) 2016-08-31 2020-01-28 Hrl Laboratories, Llc Alkali source and/or sink using ion-conducting solid electrolyte and intercalation-compound electrode
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7511482A (en) * 1975-09-30 1977-04-01 Philips Nv GAS BINDING DEVICE; PROCEDURE FOR MANUFACTURING A COLOR TELEVISION PICTURE TUBE USING THIS GAS BINDING DEVICE AND THIS MANUFACTURED COLOR TELEVISION PICTURE TUBE.
FR2521034A1 (en) * 1982-02-05 1983-08-12 Air Liquide POTASSIUM SUPEROXIDE COMPOSITIONS AND USES THEREOF
US4464133A (en) * 1982-04-05 1984-08-07 Gte Laboratories Incorporated Method of charging a vessel with mercury
US5161955A (en) * 1991-08-20 1992-11-10 Danielson Associates, Inc. High vacuum pump using bulk getter material
US5154582A (en) * 1991-08-20 1992-10-13 Danielson Associates, Inc. Rough vacuum pump using bulk getter material
US5898272A (en) * 1997-08-21 1999-04-27 Everbrite, Inc. Cathode for gas discharge lamp
US20050089627A1 (en) * 2001-10-08 2005-04-28 Konstantin Chuntonov Method of obtaining protective coatings on the surface of chemically active materials
ITMI20070301A1 (en) * 2007-02-16 2008-08-17 Getters Spa SUPPORTS INCLUDING GETTER MATERIALS AND ALKALINE OR ALKALINE-TERROSI METALS FOR THERMOREGULATION SYSTEMS BASED ON TUNNEL EFFECT
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2117735A (en) * 1936-10-01 1938-05-17 Rca Corp Getter
US3385644A (en) * 1965-06-08 1968-05-28 Getters Spa Process for filling with mercury discharge tubes and for absorbing residual noxious gases

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2117735A (en) * 1936-10-01 1938-05-17 Rca Corp Getter
US3385644A (en) * 1965-06-08 1968-05-28 Getters Spa Process for filling with mercury discharge tubes and for absorbing residual noxious gases

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US4099079A (en) * 1975-10-30 1978-07-04 U.S. Philips Corporation Secondary-emissive layers
US4459949A (en) * 1982-02-12 1984-07-17 Teves-Thompson Gmbh Liquid metal cooled internal combustion engine valves with getter
US4988318A (en) * 1983-03-10 1991-01-29 Gte Products Corporation Unsaturated vapor high pressure sodium lamp arc tube fabrication process
CN100459219C (en) * 2001-05-15 2009-02-04 工程吸气公司 Cesium dispensers and process for use thereof
KR100742424B1 (en) 2001-05-15 2007-07-24 사에스 게터스 에스.페.아. Cesium dispensers and process for the use thereof
US20040001916A1 (en) * 2001-05-15 2004-01-01 Saes Getters S.P.A. Cesium dispensers and process for the use thereof
US6753648B2 (en) 2001-05-15 2004-06-22 Saes Getters S.P.A. Cesium dispensers and process for the use thereof
US20040206205A1 (en) * 2001-05-15 2004-10-21 Saes Getters S.P.A. Cesium mixtures and use thereof
WO2002093664A3 (en) * 2001-05-15 2003-02-06 Getters Spa Cesium dispensers and process for the use thereof
WO2002093664A2 (en) * 2001-05-15 2002-11-21 Saes Getters S.P.A Cesium dispensers and process for the use thereof
US20050145179A1 (en) * 2002-09-06 2005-07-07 Saes Getters S.P.A. Accessory member for dispensers of alkali metals
WO2006027814A3 (en) * 2004-09-10 2006-05-18 Getters Spa Mixtures for evaporation of lithium and lithium dispensers
JP2008512570A (en) * 2004-09-10 2008-04-24 サエス ゲッタース ソチエタ ペル アツィオニ Compound for lithium evaporation & lithium dispenser
JP4804469B2 (en) * 2004-09-10 2011-11-02 サエス ゲッターズ ソチエタ ペル アツィオニ Compound for lithium evaporation & lithium dispenser
WO2006027814A2 (en) * 2004-09-10 2006-03-16 Saes Getters S.P.A. Mixtures for evaporation of lithium and lithium dispensers
US7625505B2 (en) 2004-09-10 2009-12-01 Saes Getters S.P.A. Mixtures for evaporation of lithium and lithium dispensers
CN100575536C (en) * 2004-09-10 2009-12-30 工程吸气公司 The mixture that is used for evaporation of lithium
US20100021623A1 (en) * 2004-09-10 2010-01-28 Saes Getters S.P.A. Lithium dispenser for lithium evaporation
US7794630B2 (en) 2004-09-10 2010-09-14 Saes Getters S.P.A. Lithium dispenser for lithium evaporation
US7842194B2 (en) 2004-11-24 2010-11-30 Saes Getters S.P.A. Dispensing system for alkali metals capable of releasing a high quantity of metals
AT501721B1 (en) * 2005-03-11 2006-11-15 Konstantin Technologies Ges M EVAPORATOR SOURCE FOR EVAPORATING ALKALI / ERDALKALIMETALLEN
US20060257296A1 (en) * 2005-05-13 2006-11-16 Sarnoff Corporation Alkali metal dispensers and uses for same
US20090266201A1 (en) * 2006-03-13 2009-10-29 Saes Getters S.P.A. Use of Magnesium-Copper Compositions for the Evaporation of Magnesium and Magnesium Dispensers
US8029597B2 (en) 2006-03-13 2011-10-04 Saes Getters S.P.A. Use of magnesium-copper compositions for the evaporation of magnesium and magnesium dispensers
CN103906854A (en) * 2011-11-11 2014-07-02 工程吸气公司 Organic-inorganic composition for the vapour release of alkali or alkali-earth metals
CN103906854B (en) * 2011-11-11 2016-08-24 工程吸气公司 For steam release alkali metal or the organicinorganic compositions of alkaline-earth metal
US10545461B1 (en) 2016-08-31 2020-01-28 Hrl Laboratories, Llc Alkali source and/or sink using ion-conducting solid electrolyte and intercalation-compound electrode
US10775748B1 (en) 2016-08-31 2020-09-15 Hrl Laboratories, Llc Alkali source and/or sink using ion-conducting solid electrolyte and intercalation-compound electrode
US10774220B1 (en) 2018-04-12 2020-09-15 Hrl Laboratories, Llc Inorganic passive coatings for atomic vapor cells
US11142651B1 (en) 2018-04-12 2021-10-12 Hrl Laboratories, Llc Inorganic passive coatings for atomic vapor cells
US11718761B1 (en) 2018-04-12 2023-08-08 Hrl Laboratories, Llc Inorganic passive coatings for atomic vapor cells
US11849532B1 (en) 2018-11-30 2023-12-19 Hrl Laboratories, Llc Electrochemical atom vapor source and/or sink with integrated heater
US11101809B1 (en) 2019-08-26 2021-08-24 Hrl Laboratories, Llc Metal vapor-density control system with composite multiphase electrode
US11869679B2 (en) 2021-03-10 2024-01-09 Hrl Laboratories, Llc Ramsey-bordé ion frequency-reference apparatus, and methods of making and using the same
US11929186B2 (en) 2021-03-10 2024-03-12 Hrl Laboratories, Llc Ramsey-Bordé ion frequency-reference apparatus, and methods of making and using the same

Also Published As

Publication number Publication date
NL6716941A (en) 1968-06-14
GB1182150A (en) 1970-02-25
US3579459A (en) 1971-05-18
DE1614678A1 (en) 1972-03-23
DE1614678B2 (en) 1972-11-02

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