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arXiv · 0912.2760

Lowering of surface melting temperature in atomic clusters with a nearly closed shell structure

A. Bagrets·R. Werner·F. Evers·G. Schneider·D. Schooss·P. Woelfle
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Abstract

We investigate the interplay of particle number, N, and structural properties of selected clusters with N=12 up to N=562 by employing Gupta potentials parameterized for Aluminum and extensive Monte-Carlo simulations. Our analysis focuses on closed shell structures with extra atoms. The latter can put the cluster under a significant stress and we argue that typically such a strained system exhibits a reduced energy barrier for (surface) diffusion of cluster atoms. Consequently, also its surface melting temperature, T_S, is reduced, so that T_S separates from and actually falls well below the bulk value. The proposed mechanism may be responsible for the suppression of the surface melting temperature observed in a recent experiments.

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A. Bagrets, R. Werner, F. Evers, G. Schneider, D. Schooss, P. Woelfle. 2009-12-14. Lowering of surface melting temperature in atomic clusters with a nearly closed shell structure. https://doi.org/10.1103/physrevb.81.075435

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