Mirror electron microscopy applied to the continuous local measurement of work-function variations

In surface studies, the mirror electron microscope (MEM) can give a picture of electrical and geometrical roughness and simultaneously a continuous measurement of local work-function changes Delta phi ; however, no critical study has been done on the accuracy of such a measurement. Using the MEM, the authors developed a new method to obtain the total electron reflection coefficient R in the very low energy range which allows them to determine accuracy and exhibit some correlations between Delta phi measurements and R variations near zero energy. By using a local deconvolution treatment for our experimental results on O/W (100), O and CO/Ni(111) and O and CO/Cu(100) the authors determined the injection threshold for monokinetic electrons. The results lead the authors to present a new sequential operating method giving R which is of great interest in the low energy range and a Delta phi measurement with controlled accuracy.