Thermodynamics of tin clusters

Joshi, Kavita ; Kanhere, D. G. ; Blundell, S. A. (2003) Thermodynamics of tin clusters Physical Review B, 67 (23). 235413_1-235413_8. ISSN 0163-1829

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Official URL: http://prb.aps.org/abstract/PRB/v67/i23/e235413

Related URL: http://dx.doi.org/10.1103/PhysRevB.67.235413

Abstract

We report the results of detailed thermodynamic investigations of the Sn20 cluster using density-functional molecular dynamics. These simulations have been performed over a temperature range of 150 to 3000 K, with a total simulation time of order 1 ns. The prolate ground state and low-lying isomers consist of two tricapped trigonal prism (TTP) units stacked end to end. The ionic specific heat, calculated via a multihistogram fit, shows a small peak around 500 K and a shoulder around 850 K. The main peak occurs around 1200 K, about 700 K higher than the bulk melting temperature, but significantly lower than that for Sn10. The main peak is accompanied by a sharp change in the prolate shape of the cluster due to the fusion of the two TTP units to form a compact, near spherical structure with a diffusive liquid like ionic motion. The small peak at 500 K is associated with rearrangement processes within the TTP units, while the shoulder at 850 K corresponds to distortion of at least one TTP unit, preserving the overall prolate shape of the cluster. At all temperatures observed, the bonding remains covalent.

Item Type:Article
Source:Copyright of this article belongs to American Physical Society.
ID Code:16169
Deposited On:15 Nov 2010 14:05
Last Modified:17 May 2016 00:58

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