On thin ice: surface order and disorder during pre-melting

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	On thin ice: surface order and disorder during pre-melting
	Bishop, CL ; Pan, D ; Liu, LM ; Tribello, GA ; Michaelides, A ; Wang, EG ; Slater, B
刊名	FARADAY DISCUSSIONS
	2009
卷号	141 页码:277
关键词	MOLECULAR-DYNAMICS HEXAGONAL ICE PHASE-DIAGRAM LIQUID WATER IH SIMULATION MODELS POINT TIP4P H2O
ISSN号	1364-5498
通讯作者	Slater, B (reprint author), UCL, Dept Chem, Christopher Ingold Bldg,20 Gordon St, London WC1H 0AJ, England.
中文摘要	The effect of temperature on the structure of the ice Ih (0001) surface is considered through a series of molecular dynamics simulations on an ice slab. At relatively low temperatures (200K) a small fraction of surface self-interstitials (i.e. admolecules) appear that are formed exclusively from molecules leaving the outermost bilayer. At higher temperatures (ca. 250 K), vacancies start to appear in the inner part of the outermost bilayer exposing the underlying bilayer and providing sites with a high concentration of the dangling hydrogen bonds. Around 250-260 K aggregates of molecules formed on top of the outermost bilayer from self-interstitials become more mobile and have diffusivities approaching that of liquid water. At similar to 270-280 K the inner bilayer of one surface noticeably destructures and it appears that at above 285 K both surfaces are melting. The observed disparity in the onset of melting between the two sides of the slab is rationalised by considering the relationship between surface energy and the spatial distribution of protons at the surface; thermodynamic stability is conferred on the surface by maximising separations between dangling protons at the crystal exterior. Local hotspots associated with a high dangling proton density are suggested to be susceptible to pre-melting and may be more efficient at trapping species at the external surface than regions with low concentrations of protons thus potentially helping ice particles to catalyse reactions. A preliminary conclusion of this work is that only about 10-20 K below the melting temperature of the particular water potential employed is major disruption of the crystalline lattice noted which could be interpreted as being "liquid", the thickness of this film being about a nanometre.
收录类别	SCI
资助信息	EURYI; EPSRC
语种	英语
公开日期	2013-09-24
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/50245]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Bishop, CL,Pan, D,Liu, LM,et al. On thin ice: surface order and disorder during pre-melting[J]. FARADAY DISCUSSIONS,2009,141:277.
APA	Bishop, CL.,Pan, D.,Liu, LM.,Tribello, GA.,Michaelides, A.,...&Slater, B.(2009).On thin ice: surface order and disorder during pre-melting.FARADAY DISCUSSIONS,141,277.
MLA	Bishop, CL,et al."On thin ice: surface order and disorder during pre-melting".FARADAY DISCUSSIONS 141(2009):277.