Features of twins and stacking faults in silver nanorice and electron-beam irradiation effect.

Systematic structural characterization using high resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED) and diffractogram analysis of silver nanorice was aimed to reveal the characteristic features of twins and stacking faults, faceting effect and smoothing phenomena of outer surfaces. Nucleation, growth and crystallization of new nanocrystals, and depletion of parent nanorice was observed by the in situ TEM through electron-beam irradiation. It can be seen that the fundamental growth mechanism of the new nucleus is Ag atom diffusion or migration through carbon film supported these crystals. Twins in the as-grown nanorice is a reflection twin with {111} lattice plane as the common plane, and they are formed by 120° or 60° rotation about the reference twin lamella. Shockley partial dislocation was formed by the {111} lattice plane shifting along the <112> direction with the Burgers vector a/6 <112>. Twin faults occur in the form of adjacent twin lamellas inserted into a single atomic plane. Growth morphology analysis suggests that {111} and {001} lattice planes with the minimum surface attachment energy have a tendency to facet.