Fast electron dynamics in small aluminum clusters: non-magic behavior of a magic cluster

Relaxation dynamics of the optically excited state in Aln− with n=6–15 were studied using time-resolved two photon photoemission spectroscopy. Relaxation rates of these Al clusters are slower than those of some d-metal clusters which can be explained by lower electron density of state in the sp-metals. The relaxation rate of Al13−, a magic cluster anion with a closed electronic shell is as fast as the non-magic clusters such as Al10−, implying that the relaxation dynamics of magic clusters cannot be rationalized by the electron–electron scattering. Origin of this unexpected behaviour of the magic cluster is discussed.