Melting behavior of nanometer sized gold isomers

• Published in: Surface science 2001-09, Vol.491 (1), p.88-98
• Main Authors: Liu, H.B, Ascencio, J.A, Perez-Alvarez, M, Yacaman, M.J
• Format: Article
• Language: English
• Subjects: Applied sciences; Clusters; Clusters, nanoparticles, and nanocrystalline materials; Computer simulations; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Gold; Metals. Metallurgy; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Phase transitions and critical phenomena; Physics; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surface melting; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(01)01351-6

In the present work, the melting behavior of nanometer sized gold isomers was studied using a tight-binding potential with a second momentum approximation. The cases of cuboctahedra, icosahedra, Bagley decahedra, Marks decahedra and star-like decahedra were considered. We calculated the temperature dependence of the total energy and volume during melting and the melting point for different types and sizes of clusters. In addition, the structural evolutions of the nanosized clusters during the melting transition were monitored and revealed. It is found that the melting process has three characteristic time periods for the intermediate nanosized clusters. The whole process includes surface disordering and reordering, followed by surface melting and a final rapid overall melting. This is a new observation, which it is in contrast with previous reports where surface melting is the dominant step.