Origin of the abnormal diffusion of transition metal atoms in rutile

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	Origin of the abnormal diffusion of transition metal atoms in rutile
	Zhu, Linggang; Ackland, Graeme; Hu, Qing-Miao; Zhou, Jian; Sun, Zhimei; Sun, ZM (reprint author), Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China.; Sun, ZM (reprint author), Beihang Univ, Int Res Inst Multidisciplinary Sci, Ctr Integrated Computat Mat Engn, Beijing 100191, Peoples R China.
刊名	AMER PHYSICAL SOC
	2017-06-01
卷号	95 期号:24 页码:-
ISSN号	2469-9950
英文摘要	Diffusion of dopant in rutile is the fundamental process that determines the performance of many devices in which rutile is used. The diffusion behavior is known to be highly sample-dependent, but the reasons for this are less well understood. Here, rutile is studied by using first-principles calculations, in order to unravel the microscopic origins of the diverse diffusion behaviors for different doping elements. Anomalous diffusion behavior in the open channel along the [001] direction is found: larger atoms including Sc and Zr have lower energy barrier for diffusion via interstitial mechanism, apparently contradicting their known slow diffusion rate. To resolve this, we present an alternate model for the overall diffusion rate of the large-size dopants in rutile, showing that parallel to the [001] channel, it is limited by the formation of the interstitial states, whereas in the direction perpendicular to [001], it proceeds via a kick-out mechanism. By contrast, Co and Ni prefer to stay in the interstitial site of rutile, and have conventional diffusion with a very small migration barrier in the [001] channel. This leads to highly anisotropic and fast diffusion. The diffusion mechanisms found in the present study can explain the diffusion data measured by experiments.; Diffusion of dopant in rutile is the fundamental process that determines the performance of many devices in which rutile is used. The diffusion behavior is known to be highly sample-dependent, but the reasons for this are less well understood. Here, rutile is studied by using first-principles calculations, in order to unravel the microscopic origins of the diverse diffusion behaviors for different doping elements. Anomalous diffusion behavior in the open channel along the [001] direction is found: larger atoms including Sc and Zr have lower energy barrier for diffusion via interstitial mechanism, apparently contradicting their known slow diffusion rate. To resolve this, we present an alternate model for the overall diffusion rate of the large-size dopants in rutile, showing that parallel to the [001] channel, it is limited by the formation of the interstitial states, whereas in the direction perpendicular to [001], it proceeds via a kick-out mechanism. By contrast, Co and Ni prefer to stay in the interstitial site of rutile, and have conventional diffusion with a very small migration barrier in the [001] channel. This leads to highly anisotropic and fast diffusion. The diffusion mechanisms found in the present study can explain the diffusion data measured by experiments.
学科主题	Physics, Condensed Matter
语种	英语
资助机构	National Natural Science Foundation of China [51401009, 61274005]; National Natural Science Foundation for Distinguished Young Scientists of China [51225205]; EPSRC [K01465X]; Royal Society Wolfson award; China MoST [2016YFB0701301]
公开日期	2018-01-10
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79183]
专题	金属研究所_中国科学院金属研究所
通讯作者	Sun, ZM (reprint author), Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China.; Sun, ZM (reprint author), Beihang Univ, Int Res Inst Multidisciplinary Sci, Ctr Integrated Computat Mat Engn, Beijing 100191, Peoples R China.
推荐引用方式 GB/T 7714	Zhu, Linggang,Ackland, Graeme,Hu, Qing-Miao,et al. Origin of the abnormal diffusion of transition metal atoms in rutile[J]. AMER PHYSICAL SOC,2017,95(24):-.
APA	Zhu, Linggang.,Ackland, Graeme.,Hu, Qing-Miao.,Zhou, Jian.,Sun, Zhimei.,...&Sun, ZM .(2017).Origin of the abnormal diffusion of transition metal atoms in rutile.AMER PHYSICAL SOC,95(24),-.
MLA	Zhu, Linggang,et al."Origin of the abnormal diffusion of transition metal atoms in rutile".AMER PHYSICAL SOC 95.24(2017):-.