Evaporative attachment of slow electrons to alkali nanoclusters

TL;DR

This paper investigates how slow electrons attach to alkali nanoclusters, revealing a detailed evaporative attachment process that explains the restructuring of anion abundance spectra and refines cluster binding energy relations.

Contribution

It introduces a quantitative framework for evaporative attachment of electrons to nanoclusters, enhancing understanding of cluster-electron interactions and updating previous energy values.

Findings

Restructured abundance spectra of Na^- clusters due to electron attachment.

Validation of a general evaporative attachment model with experimental data.

Refined binding energy relations among cationic, neutral, and anionic clusters.

Abstract

The abundance spectrum of Na^-_{n~7-140} anions formed by low energy electron attachment to free nanoclusters is measured to be strongly and nontrivially restructured with respect to the neutral precursor beam. This restructuring is explained in quantitative detail by a general framework of evaporative attachment: an electron is captured by the long-range polarization potential, its energy is transferred into thermal vibrations, and dissipated by evaporative cooling. The data also affirm a formulated relation between the binding energies of cationic, neutral, and anionic clusters, and an adjustment to the prior values of dimer evaporation energies.