Atomistic visualization of deformation was realized by dynamic high-resolution transmission electron microscopy. Compression, tensile, and shear deformation in nanometer-sized gold was carried out at room temperature inside a 200-kV transmission electron microscope using a piezodriving specimen holder. The atomic process of the deformation was observed in situ at a spatial resolution of 0.2 nm and at a time resolution of $\frac{1}{60}$ s. It was shown that slip and twinning are attributed to the deformation and proceed at every atomic layer in dislocation-free nanometer-sized gold. A dislocationlike line defect is observed during the slip and twinning processes.

• Received 23 December 1997

DOI:https://doi.org/10.1103/PhysRevB.57.11158