| 摘要 |
The object of the invention is to provide an electron source that operates at lower temperature and has a low work function having a smaller energy width. An electron source, comprising an electrical porcelain, two conductive terminals connected to the electrical porcelain, a filament formed as it extends between the conductive terminals, and a rod of the <100> single crystal of at least one metal selected from the group consisting of tungsten, molybdenum, tantalum and rhenium, connected to the filament, wherein: the rod has an electron-emitting face formed in the tip region with its {100} crystal face exposed; the rod has a diffusion source on the central region; the diffusion source is made of a mixed oxide of barium oxide group and scandium oxide; and the compositional rate of barium oxide group as BaO is 50 mol % or more and that of scandium oxide as Sc 2 O 3 10 to 50 mol % when the mixed oxide is prepared. |
