Atomistic Visualization of Mechanical Interaction in Gold Crystalline Boundaries by Time-Resolved High Resolution Transmission Electron Microscopy

The atomic processes in mechanical interaction were visualized by time-resolved high resolution transmission electron microscopy at a spatial resolution of 0.2 nm and a time resolution of 1/60 s. Nanometer-sized tips of gold were approached, contacted, bonded, deformed and fractured inside a 200 kV electron microscope using a piezo-driving specimen holder. The crystallographic boundary formed after the contact. A few layers near the surfaces and bonding boundaries were responsible for the approach, contact and bonding processes. Atomic scale mechanical tests, such as the friction test, compressing, tensile and shear deformation tests, were proposed. A new type of mechanical processing at one-atomic-layer resolution was demonstrated. Atomic scale contact or noncontact type surface scanning similar to that in atomic force microscopy was also performed with the gold tips.