Site-dependent magnetism of Ni adatoms on MgO/Ag(001)

TL;DR

This study investigates how the electronic and magnetic properties of a single Ni atom adsorbed on MgO/Ag(001) vary with binding site and Coulomb interaction strength, revealing site-dependent magnetism and energy competition.

Contribution

It provides a detailed computational analysis of site-dependent magnetism of Ni adatoms on MgO/Ag(001), highlighting the influence of Coulomb interactions and surface bonding.

Findings

Magnetic properties vary significantly across different binding sites.

Preferred adsorption site depends on the Coulomb interaction parameter U.

Comparison with Co/MgO/Ag reveals similar site-dependent behaviors.

Abstract

We examine the adsorption of a single Ni atom on a monolayer of MgO on a Ag substrate using DFT and DFT+U computational approaches. We find that the electronic and magnetic properties vary considerably across the three binding sites of the surface. Two of the binding sites are competitive in energy, and the preferred site depends on the strength of the on-site Coulomb interaction U. These results can be understood in terms of the competition between bonding and magnetism for surface adsorbed transition metal atoms. Comparisons are made with a recent experimental and theoretical study of Co on MgO/Ag, and implications for scanning tunneling microscopy experiments on the Ni system are discussed.