Sensitivity of nucleation phenomena on range of interaction potential

Singh, Rakesh S and Santra, Mantu and Bagchi, Biman (2012) Sensitivity of nucleation phenomena on range of interaction potential. In: Journal of Chemical Physics, The, 136 (8).

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Abstract

Theoretical and computational investigations of nucleation have been plagued by the sensitivity of the phase diagram to the range of the interaction potential. As the surface tension depends strongly on the range of interaction potential and as the classical nucleation theory (CNT) predicts the free energy barrier to be directly proportional to the cube of the surface tension, one expects a strong sensitivity of nucleation barrier to the range of the potential; however, CNT leaves many aspects unexplored. We find for gas-liquid nucleation in Lennard-Jones system that on increasing the range of interaction the kinetic spinodal (KS) (where the mechanism of nucleation changes from activated to barrierless) shifts deeper into the metastable region. Therefore the system remains metastable for larger value of supersaturation and this allows one to explore the high metastable region without encountering the KS. On increasing the range of interaction, both the critical cluster size and pre-critical minima in the free energy surface of kth largest cluster, at respective kinetic spinodals, shift towards smaller cluster size. In order to separate surface tension contribution to the increase in the barrier from other non-trivial factors, we introduce a new scaling form for surface tension and use it to capture both the temperature and the interaction range dependence of surface tension. Surprisingly, we find only a weak non-trivial contribution from other factors to the free energy barrier of nucleation. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3685835]

Item Type:	Journal Article
Publication:	Journal of Chemical Physics, The
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Keywords:	free energy;Lennard-Jones potential;nucleation;phase diagrams;surface tension
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	28 Mar 2012 06:04
Last Modified:	28 Mar 2012 06:04
URI:	http://eprints.iisc.ac.in/id/eprint/44089

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