The Work Functions of Au/Mg Decorated Au(100), Mg(001), and AuMg Alloy Surfaces: A Theoretical Study

TL;DR

This theoretical study uses density functional theory to predict work functions of Au/Mg decorated surfaces and AuMg alloys, revealing Mg's dominant influence due to charge transfer and surface dipole effects, with results aligning with experimental data.

Contribution

It provides a detailed theoretical analysis of work functions for Au/Mg surfaces and AuMg alloys, highlighting the role of charge transfer and surface dipoles, which was not previously characterized.

Findings

Mg-dominated work functions in Au/Mg systems

Strong charge transfer from Mg to Au enhances surface dipoles

Calculated properties of AuMg alloy agree with experimental data

Abstract

A plane-wave density functional theory is used to predict the work functions of Au/Mg decorated Au(100), Mg(001), and stochiometric AuMg alloy surfaces. We find, that irrespective of the details, all Au/Mg systems containing Mg on the surface reveal the Mg-dominated work functions, i.e. significantly shifted toward the work function of clean Mg(001) surface. The reported analyzes suggest, that this general trend stems from a strong charge transfer from Mg to Au and consequent enhancement of a surface dipole. The calculated properties of the AuMg alloy well agree to the experiment. The reported results may readily find application in Au/Mg/AuMg surface physics and technology of metal/semiconductor contacts.