Dipole excitations of Ar substrate in contact with Na clusters

TL;DR

This paper investigates how argon substrate atoms become dipole excited when in contact with sodium clusters of various charge states, highlighting the dominant role of electrostatic interactions in energy storage.

Contribution

It introduces a hierarchical model to analyze dipole excitations in argon substrates interacting with charged and neutral sodium clusters.

Findings

Charged clusters induce the largest dipole polarization in Ar atoms.

Polar clusters like Na6 also cause some polarization.

Electrostatic interactions mainly drive the dipole excitation.

Abstract

e analyze the excitation of Ar substrate in contact with Na clusters using a previously developed hierarchical model for the description of the system constituted of a highly reactive metal cluster in contact with a rather inert substrate. Particular attention is paid to the dipole excitation of the Ar atoms and the energy stored therein. The Na clusters are considered at different charge states, anions, cations, and neutral clusters for the case of deposition and a highly ionized cluster embedded in a matrix. It is found that the dipole polarization of the Ar atoms stores the largest fraction of energy in the case of charged clusters. Some, although smaller, polarization is also observed for polar clusters, as Na$_6$. The effect is predominantly induced by the electrostatic interaction.