Study on chemical state of oxygen on surface of cathodes coated with Os or W film

Why M-type cathode has higher emission performance? This is an undecided important problem for over 20 years. In this article, SRPES is used to study the chemical state of O on the surface of cathodes coated with Os or W film. It can be found that Ba/O and the content of low binding energy O species on the cathode surface coated with Os film are higher than that on W coated film remarkably. It is put forward that the surplus Ba atom is decided by the low binding energy O species. The view can be used to interpret the problem partly mentioned at the beginning.