Photodissociation spectroscopy of aluminum clusters: Al 3+-Al 6+

Abstract

The photodissociation of aluminum clusters, Al n + ( n=3–6), has been studied over a 430–650 nm wavelength range using a tunable dye laser. The product channels are Al n−1 + + Al and Al + + Al n−1 . Photodissociation spectra have been recorded with 5 nm resolution. Several features, corresponding to transitions to different excited electronic states, are apparent in the photodissociation spectra. values for dissociation energies of Al 5 + 2.20 −0.05 +0.15 eV) and Al 6 + (2.35 −0.05 +0.15 eV) have been deduced from thresholds observed in the photodissociation spectra, and from studies of the laser fluence dependence of the photoproduct signals. These values are considerably larger than the results of recent ab initio calculations.