Atomic-Scale Modeling of the Dynamics of Titanium Oxidation

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	Atomic-Scale Modeling of the Dynamics of Titanium Oxidation
	L. G. Zhu; Q. M. Hu; R. Yang; G. J. Ackland
	2012
发表期刊	Journal of Physical Chemistry C
ISSN	1932-7447
卷号	116 期号:45 页码:24201-24205
摘要	We present a model for the oxidation of titanium combining nonequilibrium statistical mechanics and density functional theory (DFT). Using this model, we found that oxygen is more strongly bound as an interstitial in Ti metal than in the oxide TiO2, the energy difference being similar to 1.6 eV. Therefore, a binary phase structure TiO2/Ti, such as the commonly observed oxide scale that protects titanium alloy against corrosion, is thermodynamically unstable. Likewise, various DFT functionals all showed that several TiO2-x compounds have lower energies than the weighted average energy of Ti and TiO2. Thus, the scale is a nonequilibrium structure for which diffusion is the controlling process. We found that the barrier for O-vacancy migration in TiO2 is E-rutile = 0.9 eV, much lower than the interface migration barriers (1.0-1.9 eV). We introduce a particle-based diffusion model that captures this feature and explains the long-lived nature of the observed thin oxide layer.
部门归属	[zhu, linggang; hu, qing-miao; yang, rui] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [zhu, linggang; ackland, graeme j.] univ edinburgh, sch phys & astron, supa, edinburgh eh9 3jz, midlothian, scotland.;hu, qm (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.;qmhu@imr.ac.cn; gjackland@ed.ac.uk
关键词	Total-energy Calculations Wave Basis-set Thermal-oxidation Films Metals Microscopy Ti2o3 Tio2
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/60537
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	L. G. Zhu,Q. M. Hu,R. Yang,et al. Atomic-Scale Modeling of the Dynamics of Titanium Oxidation[J]. Journal of Physical Chemistry C,2012,116(45):24201-24205.
APA	L. G. Zhu,Q. M. Hu,R. Yang,&G. J. Ackland.(2012).Atomic-Scale Modeling of the Dynamics of Titanium Oxidation.Journal of Physical Chemistry C,116(45),24201-24205.
MLA	L. G. Zhu,et al."Atomic-Scale Modeling of the Dynamics of Titanium Oxidation".Journal of Physical Chemistry C 116.45(2012):24201-24205.