The influence of hydrogen adsorption on magnetic properties of Ni/Cu(001) surface

TL;DR

This study examines how hydrogen adsorption affects the magnetic properties and spin-reorientation transition in Ni/Cu(001) surfaces, revealing significant geometric and magnetic changes due to hydrogen coverage.

Contribution

It provides detailed first-principles calculations showing hydrogen's impact on interlayer distances, magnetic moments, and the critical thickness for spin reorientation in Ni/Cu(001).

Findings

Hydrogen causes outward relaxation of Ni layers.

Significant decrease in local magnetic moments at the surface.

Critical thickness for spin reorientation is about 4 monolayers.

Abstract

Ni/Cu(001) is known as a unique system showing the spin-reorientation transition from an in-plane to out-of-plane magnetization direction when the Ni-overlayer thickness is increased. We investigate different relaxed multilayer structures with a hydrogen adlayer using the full-potential linearized augmented plane-wave method. The relaxed geometries, determined by total energy and atomic force calculations, show that H-monolayer strongly influences the interlayer distance between the Ni-surface and sub-surface layers yielding the outward relaxation of Ni-layer at H/Ni interface. Furthermore, large decrease of local magnetic moments at the top surface area is found for the surface covered by H. The magneto-crystalline anisotropy energies calculated for fully relaxed H/Ni-films. The spin-reorientation transition critical thickness of 4 ML is found in good quantitative agreement with the experiment.