A free energy landscape perspective on the nature of collective diffusion in amorphous solids

doi:10.1016/j.actamat.2018.07.029

IMECH-IR > 非线性力学国家重点实验室

	A free energy landscape perspective on the nature of collective diffusion in amorphous solids
	Wang YJ(王云江); Du JP ; Shinzato S ; Dai LH(戴兰宏); Ogata S
	2018-09-15
发表期刊	ACTA MATERIALIA
卷号	157 页码:165-173
ISSN	1359-6454
摘要	The nature of collective diffusion in amorphous solids is in strong contrast with diffusion in crystals. However, the atomic-scale mechanism and kinetics of such collective diffusion remains elusive. Here the free energy landscape of collective diffusion triggered by single atom hopping in a prototypical Cu50Zr50 metallic glass is explored with well-tempered metadynamics which significantly expands the observation timescale of diffusion at atomic-scale. We clarify an experimentally suggested collective atomic diffusion mechanism in the deep glassy state. The collective nature is strongly temperature-dependent. It evolves from string-like motion with only several atoms to be large size collective diffusion at high temperature, which can promote the atomic transport upon glass transition temperature. We also clarify the apparent diffusivity is dominated by the highest free energy barrier of atomic diffusion among widely distributed free energy barriers due to the dynamic heterogeneity of metallic glass, which suggests the sequential nature of diffusion is a proper assumption to the metallic glasses with dynamic heterogeneity. The temperature and pressure dependence of diffusion free energy landscape are further quantified with activation entropy, (19.6 +/- 2.5)k(B), and activation volume, (7.9 +/- 3.4) angstrom(3), which agree quantitatively with experiments. Laboratory timescale simulations of atomic diffusion brings physical insights into the unique atomic motion mechanism in non-crystalline materials. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词	Metallic glasses Collective diffusion Accelerated molecular dynamics Free energy landscape
DOI	10.1016/j.actamat.2018.07.029
URL	查看原文
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000445318800015
关键词[WOS]	METALLIC GLASSES ; MOLECULAR-DYNAMICS ; SUPERCOOLED LIQUIDS ; COOPERATIVE MOTION ; COPPER-ZIRCONIUM ; SELF-DIFFUSION ; STRAIN-RATE ; ALLOYS ; TRANSITION ; MECHANISMS
WOS研究方向	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science ; Metallurgy & Metallurgical Engineering
项目资助者	NSFC [11672299, 11790292] ; National Key Research and Development Program of China [2017YFB0702003, 2017YFB0701502] ; Strategic Priority Research Program of the Chinese Academy of Sciences [XDB22040303] ; JSPS KAKENHI [JP17H01238, JP17K18827] ; Elements Strategy Initiative for Structural Materials (ESISM)
论文分区	一类
力学所作者排名	1
引用统计
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/77854
专题	非线性力学国家重点实验室
作者单位	1.[Wang, Yun-Jiang 2.Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China 3.[Wang, Yun-Jiang 4.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China 5.[Du, Jun-Ping 6.Shinzato, Shuhei 7.Osaka Univ, Grad Sch Engn Sci, Dept Mech Sci & Bioengn, Osaka 5608531, Japan 8.[Du, Jun-Ping 9.Kyoto Univ, Ctr Elements Strategy Initiat Struct Mat ESISM, Sakyo Ku, Kyoto 6068501, Japan
推荐引用方式 GB/T 7714	Wang YJ,Du JP,Shinzato S,et al. A free energy landscape perspective on the nature of collective diffusion in amorphous solids[J]. ACTA MATERIALIA,2018,157:165-173.
APA	王云江,Du JP,Shinzato S,戴兰宏,&Ogata S.(2018).A free energy landscape perspective on the nature of collective diffusion in amorphous solids.ACTA MATERIALIA,157,165-173.
MLA	王云江,et al."A free energy landscape perspective on the nature of collective diffusion in amorphous solids".ACTA MATERIALIA 157(2018):165-173.