The Atomic Observation of the Structural Change Process in Pt Networks in Air Using Environmental Cell Scanning Transmission Electron Microscopy

The structural change in Pt networks composed of multiple chain connections among grains was observed in air at 1 atm by atomic-resolution environmental cell scanning transmission electron microscopy. An aberration-corrected incident electron probe with a wide convergence angle made it possible to increase the depth resolution that contributes to enhancing the signal-to-noise ratio of Pt network samples in air in an environmental cell, resulting in the achievement of atom-ic-resolution imaging. Dynamic observation on an atomic scale suggested that the structural change of the networks was not attributed to the surface atomic diffusion-induced step motion but mainly caused by the movement and deformation of unstable grains and grain boundaries.