Atomic process of epitaxial growth of gold on magnesium oxide studied by cross-sectional time-resolved high-resolution electron microscopy

Gold was vacuum deposited on a (001) surface of magnesium oxide inside a high-resolution electron microscope. The atomic process of epitaxial growth was observed cross sectionally in situ with time-resolved high-resolution transmission-electron microscopy. Various types of growth phenomena, such as nucleation center formation, structural fluctuations, shape modulation, secondary nucleation, and coalescence, were analyzed in real space at a spatial resolution of 0.2 nm and a time resolution of 1/60 s. It was found that a central corner of a cluster is truncated and constructed repeatedly during the growth.