The work function of W(100) surface with yttrium oxide modification measured by the onset energy profiling of the secondary electrons and by the photoemission measurement with the photoelectron emission microscope

In this study, we report that the estimations of the work function of Y-oxide/W(100) surface by measuring the onset energy of the secondary electrons using the retarding method and by measuring the photoemission using photoelectron emission microscope (PEEM). The onset energy is shifted when the work function of the sample is changed. Thus the work function of the sample can be estimated from the difference between the standard sample which the work function is well known and the sample to be measured. In this experiment, low energy electron diffraction (LEED) optics is used for the measurement setup. The PEEM method is used of photoelectric effect which the photoelectrons are emitted from the sample surface due to the incident of the light on the sample surface. The work function is estimated by the relation between the wave length of the light and the photoelectron current density.