内容简介：

Defects on metal surfaces can induce non-canonical oxidation channels that may lead to the formation of novel nanostructures. Cu surfaces have been actively researched in the due to their wide range of applications in many fields. In situ TEM experiments showed that surface step can strongly influence on the oxide nucleation on Cu surfaces. In order to better understand these results, and to provide a tight bridge between the experiment and theory, we have investigated the low-miller index Cu surface oxidation using a multiscale computational approach that employs density functional theory, reactive force field and kinetic Monte Carlo. Our results demonstrate that the step-edge defects induce markedly different oxidation dynamical behavior compared to the flat surface.  Depending on the stepped surfaces configuration, we find that the oxidation of the upper-terrace and the lower-terrace are of different preference. We show that this behavior is due to Ehrlich–Schw?bel effect, and the behavior can be largely understood using a simple bond counting argument.

报告人简介：

Dr. Saidi is an Associate Professor in the Department of Mechanical Engineering and Materials Science at the University of Pittsburgh. He received a PhD degree in Physics from The Ohio State University in 2003. Prof. Saidi’s research interests are focused on material’s design using quantum mechanical and multiscale simulations. He is an expert in computational methods that span a wide range of accuracy levels and length scales, including force-fields, density-functional theory, quantum Monte Carlo and quantum chemistry methods. More recently, Prof. Saidi has used these tools to study advanced materials for energy-related applications in solar energy, electrochemistry and photocatalysis, corrosion under extreme conditions, nanoparticle growth and morphology, ferroelectricity in oxides, and Raman spectroscopy.

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