| Popis: |
A method to perform spatially resolved work-function measurements has been developed using a modified scanning Auger microprobe (SAM). The method is based on patches of different work function giving rise to different onsets of secondary electron emission. The combined SAM work-function measurement permits a microscopic correlation of emissive or surface dipole properties with local elemental composition. The system offers a surface spatial resolution of 0.2 μm provided by the focused incident electron beam, and a work function resolution of better than 0.05 eV for most surface features of size ∼ 4.0 μm or larger. Results are presented for elemental samples which served as a test of the work-function mapping ability. Some initial results on dispenser cathode surfaces are also presented. |
