Electronic Structures of Cobalt-doped Silver Cluster Anions,AgNCo~-,Revisited:Refined Analysis of Photoelectron Spectra inLight of Chemical Reactivity

摘要

In dilute magnetic alloys,d electrons of magnetic dopants interact with s electrons of ahost metal.Although the magnitude of the s-d interaction is known to depend on thecombination of dopant and host elements,it may be modified in nanoscale because s electronsoccupy discrete levels instead of the band structure in bulk.Therefore,it is not trivial whetherd electrons are localized or delocalized in the finite size regime.This issue was tackled byphotofragmentation of transition-metal-doped silver cluster cations,AgNM~+.Thephotofragment AgnM~+ was found to show rich abundance at magic sizes with 18 valenceelectrons including 3d electrons.Another experiment on chemical reactivity revealed that themagic-size clusters exhibit a reactivity minimum.2 These results suggest that 18-electronsystems,e.g.,Ag_(10)Co~+,form a closed electronic shell by encouraging 3d delocalization.