Multicomponent rare earth boride (LaxRE1-x)B6 cathode material and preparation thereof

Abstract

A multi-component rare earth boride (LaxRE1-x)B6 cathode material and a preparation method thereof pertain to the technical field of rare earth boride hot cathode materials. At present, the research on the multi-component rare earth boride has the problems of few component systems, complicated process, etc. The component of the cathode material is (LaxRE1-x)B6, wherein, RE is one of Ce, Pr, Nd, Sm, Eu or Gd, and x is equal to or smaller than 0.2 and is equal to or larger than 0.8. The method comprises the following steps: LaH2 nano-powder and REH2 nano-powder are prepared by a DC arc evaporation method, mixed with the raw material B powder in a hypoxia environment, and sintered by spark plasma sintering (SPS) to obtain the (LaxRE1-x)B6, wherein, the sintering pressure is 30-50MPa, the heating rate is 100-200 DEG C per minute, the sintering temperature is 1,300-170 DEG C, and heat preservation lasts for 5-15min. The method has the advantages of low sintering temperature and simple process; and that the prepared cathode material has high purity, high density, excellent mechanical properties and emission performance.

Description

technical field [0001] The invention belongs to the technical field of rare earth boride hot cathode materials, in particular to a high-purity and high-density multi-element rare earth boride (La x RE 1-x )B 6 Cathode materials and methods for their preparation. Background technique [0002] In the late 1960s, foreign researchers discovered that when LaB 6 When mixed with other rare earth borides, its thermionic emission performance is better than that of LaB 6 Even better, this has sparked research interest in polynary rare earth borides. But so far, domestic and foreign research on the thermionic emission performance and application of multi-element rare earth borides is still insufficient, and the application is not widespread, mainly in two aspects: one is that there are few component systems studied, and there have been researches on them. The reported polynary rare earth borides are mainly (La-Eu)B 6 etc.; the second is the limitation of the preparation method. T...

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Problems solved by technology

But so far, domestic and foreign research on the thermionic emission performance and application of multi-element rare earth borides is still insufficient, and the application is not widespread, mainly in two aspects: one is that there are few component systems studied, and there have been researches on them. The reported polynary rare earth borides are mainly (La-Eu)B 6 etc.; the second is the limitation of the preparation method. The preparation of traditional rare earth boride cathode materials is generally divided into two steps. First, the rare earth boride powder is prepared, and then the block is prepared by hot pressing or cold pressing sintering.

These methods all have problems such as high sintering temperature, high pressure, insufficient compactness of the product, incomplete reaction, impure product, complicated process, etc., resulting in poor performance of the prepared product.

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