The absorption spectra of small nickel clusters via photodissociation: NinArm→Nin+mAr

Abstract

The photodissociation action spectra of Ni_nAr_m (n=3,4,5, and 7) have been recorded from 306 to 674 nm. The spectra are continuous, with cross sections which increase monotonically into the ultraviolet. It is observed that the photodissociation spectra recorded for Ni₃Ar_m, Ni₄Ar_m, and Ni₅Ar_m are independent on m, indicating a negligible influence of the weakly bound argon atoms on the absorption spectra of the underlying clusters. The oscillator strengths increase monotonically with increasing cluster nuclearity (n) in accord with the Thomas–Reiche–Kuhn sum rule. The results are discussed from both molecular and classical electrodynamic points of view.