Step-induced unusual magnetic properties of ultrathin Co/Cu films: ab initio study

TL;DR

This study uses ab initio calculations to reveal how submonolayer Cu alters the magnetic properties of ultrathin Co/Cu films by inducing non-collinear magnetic arrangements through electronic hybridization.

Contribution

It demonstrates the impact of submonolayer Cu on magnetic structure changes in Co/Cu films, highlighting the role of electronic hybridization at stepped surfaces.

Findings

Cu adsorption causes non-collinear magnetic arrangements.

Hybridization of Co and Cu $d$-electrons is key.

Magnetic easy axis switching occurs due to Cu layers.

Abstract

We have performed ab initio studies to elucidate the unusual magnetic behavior recently observed in epitaxial Co films upon absorption of submonolayers of Cu and other materials. We find that a submonolayer amount of Cu on a stepped Co/Cu (100) film changes dramatically the electronic and magnetic structure of the system. The effect is mainly due to hybridization of Co and Cu $d$-electrons when copper forms a ``wire'' next to a Co step at the surface. As a result, a non-collinear arrangement of magnetic moments (switching of the easy axis) is promoted. [PACS 75.70.Ak,75.70.-i]