Breakdown of universal Lindemann criterion in the melting of Lennard-Jones polydisperse solids

Sarkar, Sarmistha and Jana, Chandramohan and Bagchi, Biman (2017) Breakdown of universal Lindemann criterion in the melting of Lennard-Jones polydisperse solids. In: JOURNAL OF CHEMICAL SCIENCES, 129 (7, SI). pp. 833-840.

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Abstract

It is commonly believed that melting occurs when mean square displacement (MSD) of a particle of crystalline solid exceeds a threshold value. This is known as the Lindemann criterion, first introduced in the year of 1910 by Lindemann. However, Chakravarty et al., demonstrated that this common wisdom is inadequate because the MSD at melting can be temperature dependent when pressure is also allowed to vary along the coexistence line of the phase diagram Chakravarty C, Debenedetti P G and Stillinger F H 2007 J. Chem. Phys. 126 204508]. We show here by extensive molecular dynamics simulation of both two and three dimensional polydisperse Lennard-Jones solids that particles on the small and large limits of size distribution exhibit substantially different Lindemann ratio at melting. Despite all the dispersion in MSD, melting is found to be first order in both the dimensions at 5-10% dispersity in size. Sharpness of the transition is incommensurate with the different rate of growth of MSD. The increased MSD values of smaller particles play a role in the segregation of them prior to melting.

Item Type:	Journal Article
Publication:	JOURNAL OF CHEMICAL SCIENCES
Additional Information:	Copy right for this article belongs to the INDIAN ACAD SCIENCES, C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	29 Jul 2017 07:33
Last Modified:	29 Jul 2017 07:33
URI:	http://eprints.iisc.ac.in/id/eprint/57504

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