Well-Ordered In Adatoms at the In$_2$O$_3$(111) Surface Created by Fe Deposition

TL;DR

This study demonstrates that Fe deposition on In₂O₃(111) at room temperature creates well-ordered In adatoms, confirmed by STM imaging and DFT calculations, revealing a novel surface configuration.

Contribution

It reveals a new method to produce ordered adatom arrays on oxide surfaces via Fe deposition, involving Fe-In exchange mechanisms.

Findings

Ordered In adatoms observed after Fe deposition.

DFT confirms Fe-In exchange causes adatom formation.

Surface structure differs from typical defect-driven nucleation.

Abstract

Metal deposition on oxide surfaces usually results in adatoms, clusters, or islands of the deposited material, where defects in the surface often act as nucleation centers. Here an alternate configuration is reported. After the vapor deposition of Fe on the In$_2$O$_3$(111) surface at room temperature, ordered adatoms are observed with scanning tunneling microscopy. These are identical to the In adatoms that form when the sample is reduced by heating in ultrahigh vacuum. Density functional theory (DFT) calculations confirm that Fe interchanges with In in the topmost layer, pushing the excess In atoms to the surface where they arrange as a well-ordered adatom array.