# Ultrafast charge transfer processes accompanying KLL Auger decay in aqueous KCl solution

## TL;DR

This study investigates ultrafast charge transfer during KLL Auger decay in aqueous KCl, revealing charge-dependent differences in spectra and highlighting the role of solvent interactions in charge redistribution.

## Contribution

It provides new insights into charge transfer mechanisms during Auger decay in solvated ions, combining experimental spectra with ab initio calculations.

## Key findings

- Strong satellite peak in K$^+$ Auger spectrum linked to electron transfer from water.
- No such peak observed for Cl$^-$, indicating charge dependence.
- Charge transfer processes influence charge redistribution after core-hole creation.

## Abstract

X-ray photoelectron spectroscopy (XPS) and KLL Auger spectra of aqueous KCl solution were measured for the K$^+$ and Cl$^-$ edges. While the XPS spectra of potassium and chloride have similar structures, both exhibiting only weak satellite structures near the main line, the Auger spectra of these isoelectronic ions differ dramatically. A very strong satellite peak was found in the K$^+$ KLL Auger spectrum at the low kinetic energy side of the $^1$D state. Using equivalent core models and ab initio calculations this spectral structure was assigned to electron transfer processes from solvent water molecules to the solvated K$^+$ cation. Contrary to the potassium case, no extra peak was found in the KLL Auger spectrum of solvated Cl$^-$ indicating on a strong dependence of the underlying processes on ionic charge. The observed charge transfer processes are suggested to play an important role in charge redistribution following single and multiple core-hole creation in atomic and molecular systems placed into an environment.

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Source: https://tomesphere.com/paper/1704.00065