Electron microscopic investigations of MgO morphology and surfaces

Abstract

Surface detail on magnesium oxide derived from oxidation of the metal and calcination of the basic carbonate has been studied by means of direct transmission electron microscopy. Many of the classical features of step growth have been observed at the unit cell level. In some dislocation-free crystals, surfaces have been found which closely approach two and three-level models. Both rough and smooth vicinal faces [in the sense of Burton, Cabrera and Frank1)] have been observed. In some instances aggregates of only a few dozens of ions have been observed grouped into unit cells aligned with the main crystal. By observing surface detail and thickness fringes simultaneously the existence of extremely high-index mean faces has been established. Sintered intergrowth showing both perfect and imperfect alignment has been observed.