Magnetomechanical coupling and ferromagnetic resonance in magnetic nanoparticles

TL;DR

This paper develops a theory for the coupled mechanical and magnetic dynamics in single-domain magnetic nanoparticles, revealing sharp low-frequency resonances and potential motor applications driven by magnetomechanical effects.

Contribution

It introduces a comprehensive model of magnetomechanical coupling in nanoparticles, highlighting the role of magnetic anisotropy and resonance phenomena.

Findings

Low-frequency satellite peaks in microwave absorption due to anisotropy

Sharp low-frequency resonances with high maxima

Nanoparticles can function as electromagnetic-mechanical energy converters

Abstract

We address the theory of the coupled lattice and magnetization dynamics of freely suspended single-domain nanoparticles. Magnetic anisotropy generates low-frequency satellite peaks in the microwave absorption spectrum and a blueshift of the ferromagnetic resonance (FMR) frequency. The low-frequency resonances are very sharp with maxima exceeding that of the FMR, because their magnetic and mechanical precessions are locked, thereby suppressing Gilbert damping. Magnetic nanoparticles can operate as nearly ideal motors that convert electromagnetic into mechanical energy. The Barnett/Einstein-de Haas effect is significant even in the absence of a net rotation.