Multiple silicon nanotwins formed on the eutectic silicon particles in Al–Si alloys

Multiple precipitating nanotwins of {1 1 1}/[1 1 2] type have been observed forming on the eutectic Si particles in Al–Si alloys upon annealing. High-resolution transmission electron microscopy (HRTEM) reveals that these precipitating nanotwins may possess very rich microstructures, including 5-fold nanotwins and various twin junctions. The formed Si nanotwins are very thin objects that are naturally appropriate for HRTEM observations. It is very likely that the formation and the morphology of the nanotwins are related to the aging conditions.