First-principles investigation of spin wave dispersions in surface-reconstructed Co thin films on W(110)

TL;DR

This study uses first-principles calculations to analyze spin wave dispersions in surface-reconstructed Co thin films on W(110), revealing the influence of electronic hybridization at the interface and comparing results with experimental data.

Contribution

The paper provides a detailed first-principles analysis of spin wave dispersions in Co/W(110) films, emphasizing the role of electronic hybridization and interface effects, which were not thoroughly explored before.

Findings

Strong hybridization at the Co-W interface affects magnetic interactions.

Good agreement with experimental EELS data after correction for spin splitting.

Oscillatory behavior of exchange interactions depends on film thickness.

Abstract

We computed spin wave dispersions of surface-reconstructed Co films on the W(110) surface in the adiabatic approximation. The magnetic exchange interactions are obtained via first-principles electronic structure calculations using the Korringa-Kohn-Rostoker Green function method. We analyze the strength and oscillatory behavior of the intralayer and interlayer magnetic interactions and investigate the resulting spin wave dispersions as a function of the thickness of Co films. In particular, we highlight and explain the strong impact of hybridization of the electronic states at the Co-W interface on the magnetic exchange interactions and on the spin wave dispersions. We compare our results to recent measurements based on electron energy loss spectroscopy [E. Michel, H. Ibach, and C.M. Schneider, Phys. Rev. B 92, 024407 (2015)]. Good overall agreement with experimental findings can be obtained by considering the possible overestimation of the spin splitting, stemming from the local spin density approximation, and adopting an appropriate correction.