Eur. Phys. J. D 45, 301-308 (2007)
https://doi.org/10.1140/epjd/e2007-00283-5

Combined experimental and theoretical study of small aluminum oxygen clusters^*

¹ Laboratorium voor Vaste-Stoffysica en Magnetisme & INPAC, Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, 3001 Leuven, Belgium
² Center for Computational Chemistry, Department of Chemistry, University of Georgia, Athens, 30602 Georgia, USA

Corresponding author: ^a peter.lievens@fys.kuleuven.be

Received: 10 May 2007
Revised: 18 June 2007
Published online: 5 October 2007

Abstract

We report a combined experimental and computational investigation of small Al_nO_m species (n ≤20, m ≤ 12), produced in a laser vaporization cluster source. The oxygen content in the clusters was tuned by varying the oxygen concentration in the carrier gas. Ionization energies are bracketed using different ionizing photon energies in the energy range between 5.37 and 7.89 eV. Among the singly doped Al_nO species, Al₃O and Al₁₅O are found to have relatively low ionization energies, which can be related to the magic character of the corresponding cations. Peculiarly low ionization energies also are observed for specific oxygen rich species (m > 1), suggesting the formation of ionically bound subunits. The structures and ionization energies of singly doped Al_nO^0,+ (n = 1 - 7) clusters were determined using density functional theory (B3LYP/6-311+G(d)).