Density Functional Theory Study of Structural Evolution, Relative Stability, and Electronic Properties of Sn_nAl_n (n = 2–12) Clusters

Abstract

The ground‐state structure, average binding energy (E b ), fragmentation energies (ΔE), second‐order difference energy (Δ 2 E), gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO‐LUMO), vertical ionization potential (VIP), vertical electron affinity (VEA), and charge transfer of Sn n Al n (n = 2–12) clusters were evaluated by density functional theory (DFT). With an increase in the cluster size n, Al atoms aggregated in the geometric center of the cluster, and Sn atoms encapsulated Al atoms in the periphery of the cluster. The variation of ΔE, Δ 2 E, the HOMO‐LUMO gap, VIP, and VEA of the Sn n Al n clusters followed similar trends, with certain odd‐even oscillations. However, beyond the cluster size n ≥ 9, the HOMO‐LUMO gap decreased significantly, and the VIP and VEA fluctuated significantly, indicating a deterioration of the relative stability of the cluster. Charge transfer proceeded from the Sn atom to the Al atom. This study provides an analysis of the interaction between Sn and Al at the atomic level and explains the segregation phenomenon during the preparation of tin‐aluminum alloys.This article is protected by copyright. All rights reserved.