Atomic Scale Dynamic Process of Cu Oxidation Revealed By Correlated in situ Environmental TEM and DFT Simulations

Surface oxidation of metals and alloys is omnipresent in oxidizing environments, such as air or humid conditions. The oxidation of metals and alloys not only causes problems like corrosion and degradation, but could also be used in applications such as catalysts and transistors. With the increase of application demands toward the nanoscale, a fundamental understanding of the atomic mechanisms responsible for surface oxidation is essential for the prevention, prediction, and controlled growth of metal oxide. Ample studies on the bulk oxidation of metals and alloys using bulk corrosion experimental approaches, such as Thermogravimetric Analysis (TGA), and on the initial interaction and reconstruction of metal surfaces with oxygen using surface science approaches, including Scanning Tunneling Microscopy (STM), have been completed. However, the nucleation and growth of metal oxides is much less investigated, especially at the atomic scale, since neither of these approaches can evaluate these dynamic processes. The flourishing of the in situ TEM technique, especially the development of Environmental TEM (ETEM), is very suitable and promising for narrowing this knowledge gap.