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Electronic emitting material of molybdenum rare earth containing cerium and preparation process thereof

An electron emission material and emission material technology, applied in the field of rare earth refractory metal cathode materials, can solve the problems that cannot meet the requirements of electron tubes and magnetrons

Inactive Publication Date: 2006-12-20
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the limitation of its thermal emission and secondary emission level, it cannot meet the requirements for the use of electron tubes and magnetrons with higher cathode emission capabilities, so it is still necessary to develop new cathode materials

Method used

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  • Electronic emitting material of molybdenum rare earth containing cerium and preparation process thereof
  • Electronic emitting material of molybdenum rare earth containing cerium and preparation process thereof
  • Electronic emitting material of molybdenum rare earth containing cerium and preparation process thereof

Examples

Experimental program
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Effect test

example 1

[0015] Example 1, 9.985 grams of cerium nitrate, 176.698 grams of ammonium molybdate, and 100 grams of citric acid were dissolved in water respectively, then the cerium nitrate solution and the ammonium molybdate solution were mixed, and precipitation occurred. The citric acid solution was slowly added, and the precipitation gradually dissolved. The mixed solution was heated in a 60°C water bath until the solution became a sol. The colloid is dried at 150°C, and the powder is decomposed in the atmosphere at 550°C to remove C and N elements in the colloid. Keep it in a hydrogen furnace at 550°C for 4 hours, then raise the temperature to 900°C for 1 hour, and the doped CeO obtained by reduction treatment 2 (CeO 2 Molybdenum powder with a content of 4% wt) is made into a rare earth molybdenum sintered body with a certain size by powder metallurgy. After machining, a φ3×1mm rare earth molybdenum sheet is made, which is buried in active C powder and carbonized at 1600°C under a h...

example 2

[0016] Example 2, 18.9221 grams of cerium nitrate, 63.4676 grams of yttrium nitrate, 128.7938 grams of ammonium molybdate, and 100 grams of citric acid were dissolved in water respectively, then cerium nitrate, yttrium nitrate and ammonium molybdate solution were mixed, and the citric acid solution was slowly added, The mixed solution was heated in a water bath at 80°C until the solution became a sol. Dry the colloid at 120°C, and decompose the powder in the atmosphere at 500°C to remove C and N elements in the colloid. Keep the temperature in a hydrogen furnace at 500°C for 3h, then increase the temperature to 950°C for 2 hours, and the doped Ce obtained by reduction treatment 2 o 3 and Y 2 o 3 (Ce 2 o 3 and Y 2 o 3 The total amount is 30%wt, where Ce 2 o 3 : Y 2 o 3 =1:3, mass ratio) molybdenum powder, using powder metallurgy method, made of rare earth molybdenum sintered body with a certain size. After machining, a rare earth molybdenum sheet of φ10×1.5mm is mad...

example 3

[0017] Example 3, 25.2295 grams of cerium nitrate, 56.4157 grams of yttrium nitrate, 128.7938 grams of ammonium molybdate, and 100 grams of citric acid were dissolved in water respectively, then cerium nitrate, yttrium nitrate and ammonium molybdate solution were mixed, and the citric acid solution was slowly added, The mixed solution was placed in a water bath at 90°C until the solution became a sol. The colloid is dried at 100°C, and the powder is decomposed in the atmosphere at 500°C to remove the C and N elements in the colloid. Keep the temperature in a hydrogen furnace at 500°C for 2h, then increase the temperature to 1000°C for 1h, and the doped Ce obtained by reduction treatment 2 o 3 and Y 2 o 3 (Ce 2 o 3 and Y 2 o 3 The total amount is 30%wt, where Ce 2 o 3 : Y 2 o 3 =1:2, mass ratio) molybdenum powder, using powder metallurgy method, made of rare earth molybdenum sintered body with a certain size. After machining, a rare earth molybdenum sheet of φ10×1mm...

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Abstract

A Ce contained Re-Mo material as cathode for emitting electrons contains proportionally Ce2O3 or Ce2O3 plus Y2O3 and Mo. Its preparing process includes such steps as proportionally adding the aqueous solution of RE nitrate to the aqueous solution of ammonium polybdate, adding solution of citric acid, heating by water bath, baking to become gel, removing C and N at 500-550 deg.C, two-step reducing in H2 to obtain Mo powder, and powder metallurgy.

Description

technical field [0001] A cerium-containing rare earth molybdenum electron emission material and a preparation method thereof belong to the technical field of rare earth refractory metal cathode materials. Background technique [0002] At present, ThO is mainly used in high-power electron tubes and magnetrons. 2 Cathode (respectively ThO 2 -W hot cathode and ThO 2 -W cermet cathode and ThO 2 refractory metal sponge cathode), but because Th is a radioactive element with a long half-life, it will cause serious harm to the human body and the environment during the production of materials and the preparation of the cathode, so it is required to develop new materials to replace it. Rare earth molybdenum hot cathodes and secondary emitter materials containing lanthanum have been developed in the past [1-2] , [1] for Wang Jinshu, Zhou Meiling, Zhang Jiuxing, etc., La 2 o 3 -Research on the Mechanism of Carbonization Layer on Mo Cathode Surface, Acta Metall Sinica, 11(2000) 120...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/50C04B35/624
Inventor 王金淑刘伟周美玲
Owner BEIJING UNIV OF TECH