Impact of organic capping layer on the magnetic anisotropy of ultrathin Co films

TL;DR

This study demonstrates that applying an organic hydrocarbon capping layer significantly enhances the perpendicular magnetic anisotropy of ultrathin cobalt films by modifying surface charge and inducing an electric field at the interface.

Contribution

It reveals how organic capping layers influence magnetic anisotropy in ultrathin Co films through interface effects, a novel insight into surface engineering for magnetic properties.

Findings

Organic capping increases surface anisotropy in Co films.

Enhanced perpendicular magnetic anisotropy observed with hydrocarbon layer.

Electric field at interface modifies surface atom charge configuration.

Abstract

Using combined magnetometry and ferromagnetic resonance studies, it is shown that introduction of a hydrocarbon cover layer leads to an increase of the contribution of the surface anisotropy to the effective magnetic anisotropy energy of hexagonal close-packed 0001 cobalt films, largely enhancing the perpendicular anisotropy. Due to a weak electronic interaction of the organic molecules with the Co atoms, an increase of surface anisotropy could be explained by the presence of an electric field at the organic-material/Co interface and by modification of surface atoms charge configuration.