Initial Oxidation of γ-TiAl（111） Surface:Density-functional Theory Study

Hong Li1,2),Shaoqing Wang1) and Hengqiang Ye1,3) 1) Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China 2) Graduate School of Chinese Academy of Sciences,Beijing 100039,China 3) Electron Microscope Lab,Peking University,Beijing 100871,China

摘 要：In this paper,we reported a first-principles investigation on the structural and electronic properties of O adsorption on the γ-TiAl（111） surface,to illustrate the oxidation process.It has been found that:（1） rather than stopping with one full monolayer of coverage,oxygen adsorption continues till two monolayer coverage,rendering an oxide-like structure;（2） full structural relaxation makes the surface oxide layer denser and more stable,which hinders the subsequent O adsorption（oxidation） process.In addition,the transformation from metal to oxide surface was identified by analyzing the local density of states through the oxidation steps,which was in good agreement with experimental results.

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