RT info:eu-repo/semantics/article
T1 Electronic effects on melting: Comparison of aluminum cluster anions and cations
A1 Starace, Anne K.
A1 Neal, Colleen M.
A1 Cao, Baopeng
A1 Jarrold, Martin F.
A1 Aguado Rodríguez, Andrés
A1 López Rodríguez, José Manuel
K1 Líquidos-Propiedades térmicas
K1 Sólidos-Propiedades eléctricas
AB Heat capacities have been measured as a function of temperature for aluminum cluster anions with 35–70 atoms. Melting temperatures and latent heats are determined from peaks in the heat capacities; cohesive energies are obtained for solid clusters from the latent heats and dissociation energies determined for liquid clusters. The melting temperatures, latent heats, and cohesive energies for the aluminum cluster anions are compared to previous measurements for the corresponding cations. Density functional theory calculations have been performed to identify the global minimum energy geometries for the cluster anions. The lowest energy geometries fall into four main families: distorted decahedral fragments, fcc fragments, fcc fragments with stacking faults, and “disordered” roughly spherical structures. The comparison of the cohesive energies for the lowest energy geometries with the measured values allows us to interpret the size variation in the latent heats. Both geometric and electronic shell closings contribute to the variations in the cohesive energies (and latent heats), but structural changes appear to be mainly responsible for the large variations in the melting temperatures with cluster size. The significant charge dependence of the latent heats found for some cluster sizes indicates that the electronic structure can change substantially when the cluster melts.
PB American Institute of Physics
YR 2009
FD 2009
LK http://uvadoc.uva.es/handle/10324/2452
UL http://uvadoc.uva.es/handle/10324/2452
LA eng
NO Journal of Chemical Physics, v. 131, n. 4 (2009), p.1- 11
NO Producción Científica
DS UVaDOC
RD 11-jul-2024