Neutralization of low energy Na$^{+}$ scattered from InAs(001)

TL;DR

This study measures and models the neutralization of low energy Na+ ions scattered from InAs(001) surfaces, revealing that neutralization depends on surface atomic and electronic structures, with a modified charge transfer model applicable to inhomogeneous surfaces.

Contribution

It introduces a modified resonant charge transfer model that accounts for surface inhomogeneity and atomic structure in ion neutralization processes.

Findings

Neutralization probability is higher for As sites than In sites.

A modified model combining molecular dynamics and DFT explains neutralization.

Surface atomic and electronic structures significantly influence ion neutralization.

Abstract

The neutralization probability of low energy Na$^{+}$ ions scattered from In- and As-rich InAs(001) surfaces is measured by time-of-flight spectroscopy. It is found that the neutralization probability for projectiles scattered from As sites is larger than from In sites for both types of surfaces. A modification of the resonant charge transfer model is proposed in which a freezing contour that follows the atomic structure is combined with molecular dynamics and density functional theory. Together, these approaches show that the neutralization of alkali projectiles scattered from a compound solid material is determined by multiple factors, particularly the surface atomic and electronic structures. This model is applicable to any system in which the surface potential is inhomogeneous, such as compound materials and adsorbate-covered surfaces.