|About this Abstract
||Materials Science & Technology 2012
||MS&T'12 Poster Session
||E10: First-Principles Calculations of Oxygen Diffusion Coefficients in Nickel
||Huazhi Fang, Shunli Shang, Yi Wang, Zikui Liu
|On-Site Speaker (Planned)
The diffusion of oxygen is a critical kinetic process during the internal oxidation of nickel and nickel-based alloys. In current work, we report the prediction of oxygen diffusion coefficients entirely from first-principles calculations, based on density functional theory (DFT). The diffusion coefficients of oxygen in fcc nickel will be evaluated based on both vacancy and interstitial mechanisms and the saddle states will be searched by the climb nudged elastic band (CINEB) method. For the vacancy mechanism, the five-frequency model will be used. For the interstitial mechanism, two different migration paths will be considered: one is jumping from octahedral site (O site) to a neighboring O site passing through an adjacent tetrahedral site (T site) (O-T-O), the other is jumping from O site to a neighboring O site directly (O-O). The calculated diffusion coefficients and migration barriers will be compared to experimental data and the realistic diffusion mechanism will be suggested.
||Definite: A CD-only volume