In-Situ Observation of Cooperative Grain Boundary Sliding and Migration in the Nano-Twinned Nanocrystalline-Au Thin-Films

Abstract

Using our homemade tensile device inside a transmission electron microscope, we in-situ investigated the deformation behaviours of the nano-twinned nanocrystalline Au thin-films with thickness of ~ 15 nm and average grain size of ~ 16 nm. Our extensive in-situ observation studies reveal that the deformation of the nano-twinned nanocrystalline Au thin-films was dominated by the cooperative grain boundary sliding and migration, which were rarely observed in the previous reports. Meanwhile, our statistic shows that the nano-twins tended to promote further stress-driven grain growth, and the promotion became more remarkable for the nano-twinned grains that were located at the crack tips.