RT info:eu-repo/semantics/article T1 Coulomb barriers in the dissociation of doubly charged clusters A1 Garcias, Francesca A1 Alonso Martín, Julio Alfonso A1 López Rodríguez, José Manuel A1 Barranco, Manuel K1 Física nuclear AB The barrier height for the most asymmetric fission decay of doubly charged sodium clusters(Na_N^2+) into singly ionized fragments has been computed with use of density-functional theory andthe jellium model. We have found that the barrier is sizable for large or intermediate-size clusters,but vanishes for N<=9. We have also computed the energy DeltaH_e, needed to evaporate a neutralmonomer from Na_N ^2+. For N<=40, the barrier height is smaller than DeltaH_e and emission of a Na^+ion is the preferred decay channel of hot Na_N^2+ clusters. On the other hand, the barrier height islarger than DeltaH_e, for N>40 and, in this case, monomer evaporation becomes competitive. The criticalcluster size, N_c=40, for the transition from one decay mode to the other is in reasonable agreementwith the experimental result. Our calculations suggest that the mechanism for neutralmonomerevaporation is different from the one currently assumed. PB The American Physical Society YR 1991 FD 1991 LK http://uvadoc.uva.es/handle/10324/2519 UL http://uvadoc.uva.es/handle/10324/2519 LA eng NO Physical Review B, v. 43, n. 12, (1991), p. 9459-9466 NO Producción Científica DS UVaDOC RD 28-mar-2024