We are interested in the initial stages of oxidation of Mg(0001) with the goal of understanding the process in a simple system in order to extend this understanding to the interpretation of more complicated systems. Mg oxidation has been investigated from the standpoint of corrosion since magnesium alloys have poor corrosion resistance. This restricts their use in some applications, for example in the aerospace industry, where their high strength/weight ratios would otherwise be extremely useful. MgO is also useful as a thin film insulator in semiconductor devices, as a ceramic that is easily bonded to metals, and as a catalyst support in the petrochemical industry. MgO is also used as a buffer material for thin films.

STM image of Mg(0001) exposed to 0.2 L oxygen. Note the fuzzy terrace edges caused by the motion of edge Mg atoms. The arrow points to one of several vertical streaks most likely caused by the tip picking up and redepositing atoms during the vertical scanning.

Consecutive STM scans following 1 L O₂-exposure of the same region shown above. In each panel, the top two arrows show regions where Mg atoms were removed and the bottom arrow shows a region where a new terrace was formed.

STM image at 6 L O₂-exposure showing the bumps of 3.6 A height and 60 A base diameter. The abnormal pillar observed above is again indicated by the arrow.

STM image at 20 L O₂-exposure showing the increase in the number of protrusions.