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The ion implanting method has been taken for implanting lanthanum ions into the surface layer of molybdenum wires in order to study the function of carbide layer on the surface of La 2O 3 Mo cathode in the emission. The function mechanism has been discussed by using XPS and AES methods. The results show that the carbide layer mainly acts as a reduction reagent to produce metallic lanthanum. Moreover, it can store the activator substance and carry them to the surface. Based on the research results, the carbonization technique has been changed. By applying the new technique, the lifetime of the La 2O 3 Mo cathode has been improved from 14 h to more than 1 000 h—the minimum lifetime for practical uses. [
The ion implanting method has been taken for implanting lanthanum ions into the surface layer of molybdenum wires in order to study the function of carbide layer on the surface of La 2O 3 Mo cathode in the emission. The function mechanism has been discussed by using XPS and AES results. The results show that the carbide layer mainly acts as a reduction reagent to produce metallic lanthanum. Moreover, it can store the activator substance and carry them to the surface. Based on the research results, the carbonization technique has been changed. By Apply the new technique, the lifetime of La 2O 3 Mo cathode has been improved from 14 h to more than 1000 h-the minimum lifetime for practical uses. [