Low energy Auger and loss electron spectra from magnesium and its oxide

Data have been obtained from Auger and energy loss processes in clean metallic Mg, Mg during stages of oxidation, and UHV cleaved MgO(100) surfaces. Particular attention has been paid to twenty features below 200 eV in the Auger spectra from these surfaces. A comparison of spectra from the metal, oxidised metal surface, and single crystal MgO has enabled estimates to be made of surface charging effects, and the MgO steady state surface potential is found to be near + 10 V above ground. All the Auger features are given assignments, two of which are interfacial processes involving ionic initial states and metallic final states. Several features in the low energy Auger spectrum are attributed to diffraction of true secondary electrons.