Layer-resolved study of Mg atom incorporation at MgO/Ag(001) buried interface

TL;DR

This study uses advanced x-ray techniques and calculations to analyze Mg atom incorporation at the MgO/Ag(001) interface, demonstrating control over atomic integration and its effects on electronic properties.

Contribution

It introduces a layer-resolved method to monitor Mg atom incorporation at the buried interface and shows how Mg flux exposure modifies interface and film electronic properties.

Findings

Layer-resolved shift observed in Mg Auger transition.

Mg atom incorporation can be controlled via Mg flux exposure.

Significant reduction in work function during Mg exposure.

Abstract

By combining x-ray excited Auger electron diffraction experiments and multiple scattering calculations we reveal a layer-resolved shift for the Mg KL23L23 Auger transition in MgO ultrathin films (4-6 \AA) on Ag(001). This resolution is exploited to demonstrate the possibility to control Mg atoms incorporation at the MgO/Ag(001) interface by exposing the MgO films to a Mg flux. A substantial reduction of the MgO/Ag(001) work function is observed during the exposition phase and reflects, both band-offset variations at the interface and band bending effects in the oxide film.