Electron-beam-induced Surface Reconstructing in Vermicular Alumina

The surface reconstructing of vermicular alpha-alumina exposed under electron-beam irradiation was investigated by a scanning electron microscope with 0.5 keV beam energy and by a transmittance electron microscope at room temperature and 90 K, respectively. The in-situ recorded results showed that the present electron-beam-induced surface reconstructing was both electron dose and temperature dependent and accompanied by bulk shape change. The surface reconstruction was explained by an Auger decay process, in which surface composition constancy was proposed by the equilibrium between electron stmulated reduction of Al2O3 and oxidation of aluminum by desorbed oxygen from bulk.