Premium
Molecular Dynamics Studies of the Kinetics of Phase Changes in Clusters IV: Crystal Nucleation from Molten (NaCl) 256 and (NaCl) 500 Clusters
Author(s) -
Li XiaoHua,
Huang JinFan
Publication year - 2003
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20030211206
Subject(s) - nucleation , chemistry , molecular dynamics , classical nucleation theory , cluster (spacecraft) , thermodynamics , melting point , atmospheric temperature range , phase (matter) , chemical physics , kinetics , activation energy , crystal (programming language) , molecule , crystallography , computational chemistry , physics , organic chemistry , quantum mechanics , computer science , programming language
Molecular dynamics computer simulation based on the Born‐Mayer‐Huggins potential function has been carried out to study the effects of cluster size and temperature on the nucleation rate of sodium chloride clusters in the temperature range of 580 K to 630 K. Clusters with 256 and 500 NaCI molecules have been studied and the results have been compared with those obtained from 108 molecule clusters. The melting point ( MP ) of the dusters were observed to increase with the size of the clusters and can be well described by a linear equation MP = 1107(37)‐1229(23) N −1/3 ( N is the number of molecules in the cluster). The nucleation rate was found to decrease with increasing the cluster size or temperature. Various nucleation theories have been used to interpret the nucleation rates obtained from this molecular dynamics simulation. It is possible to use a constant diffuse interface thickness to interpret the nucleation rate from the diffuse interface theory in the temperature range of this study. However, the interfacial free energy estimated from classical nucleation theory and diffuse interface theory increases too fast with increasing the temperature while that from Gran‐Gunton theory does not change with changing temperatures. The sizes of critical nuclei estimated from all the theories are smaller than those estimated from our simulations.