The influence of oxygen and hydrogen adsorption on the magnetic structure of the ultrathin iron film on the Ir(001) surface

TL;DR

This study uses ab initio calculations to explore how oxygen and hydrogen adsorption alter the magnetic structure of an ultrathin iron film on Ir(001), revealing induced antiferromagnetic order detectable by STM.

Contribution

It demonstrates that oxygen and hydrogen adsorption induce a p(2×1) antiferromagnetic order in Fe/Ir(001), expanding understanding of surface magnetic modifications due to adsorbates.

Findings

Oxygen adsorption increases interlayer distance significantly.

Both oxygen and hydrogen induce p(2×1) antiferromagnetic order.

Simulated STM images suggest magnetic order detection with non-magnetic tips.

Abstract

We present a detailed ab initio study of the electronic structure and magnetic order of an Fe monolayer on the Ir(001) surface covered by adsorbed oxygen and hydrogen. The results are compared to the clean Fe/Ir(001) system, where recent intensive studies indicated a strong tendency towards an antiferromagnetic order and complex magnetic structures. The adsorption of an oxygen overlayer significantly increases interlayer distance between the Fe layer and the Ir substrate, while the effect of hydrogen is much weaker. We show that the adsorption of oxygen (and also of hydrogen) leads to a p(2$\times $1) antiferromagnetic order of the Fe moments, which is also supported by an investigation based on a disordered local moment state. Simulated scanning tunneling images using the simple Tersoff-Hamann model hint that the proposed p(2$\times $1) antiferromagnetic order could be detected even by non-magnetic tips.