Introduction and characteristics of cerium hexaborate

Cerium hexaboride (CeB6) has become a cathode material with high electron emissivity due to its low work function. It is more resistant to carbon pollution and has a longer life than the lanthanum boride cathode. It is widely used in electron microscopy, microwave tubes, electron beam etching, electron beam welding, X-ray tubes and free-electron laser. Cerium hexaborate crystal has been successfully applied in desktop scanning electron microscopes, becoming an excellent and stable filament material. Cerium hexaboride (CeB6, also known as cerium boride, CeBix, CEBIX, sometimes written as CeB) is a inorganic compound. Cerium hexaborate (CeB6) has a CsCl structure (belonging to a simple cubic crystal system, with large spheres representing the Ce element). The difference is that B6 octahedral clusters occupy the position of Cl, while Ce occupies the position of Cs. It is a kind of refractory ceramic material. Its low work function makes it one of the cathode materials with the highest known electron emissivity. At the same time, it is very stable in vacuum. The normal operating temperature of cerium hexaborate is 1450 ° C. Cerium hexaborate, like lanthanum hexaborate, slowly evaporates during cathode operation. The CeB6 cathode can maintain its optimal shape for a longer period of time at an operating temperature of 1850 K, resulting in a longer lifespan. At the same time, due to its evaporation rate being about 30% slower than lanthanum borate, the thermal cathode coating of cerium borate is more difficult to remove than lanthanum borate.





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