Analysis of the Collective Behavior of a 10 by 10 Array of Fe3O4 Dots in a Large Micromagnetic Simulation

TL;DR

This paper presents a comprehensive 3D micromagnetic simulation of a 10x10 array of Fe3O4 dots, revealing complex collective magnetic behaviors and mode interactions that differ from single-particle responses, with implications for magnonic device design.

Contribution

It introduces detailed simulation results of a large ferrite dot array, highlighting mode-shifting, splitting, and symmetry effects not observed in isolated particles.

Findings

Mode-shifting and splitting in the array's power spectrum.

Inversion symmetry in magnetization modes across the array.

Potential applications in coherent spin-wave excitation control.

Abstract

We report a full (3D) micromagnetic simulation of a set of 100 ferrite (Fe$_3$O$_4$) cylindrical dots, arranged in a 10 by 10 square (planar) array of side 3.27 $\mu$m, excited by an external in-plane magnetic field. The resulting power spectrum of magnetic excitations and the dynamical magnetization field at the resulting resonance modes were investigated. The absorption spectrum deviates considerably from that of a single particle reference simulation, presenting a mode-shifting and splitting effect. We found an inversion symmetry through the center of the array, in the sense that each particle and its inversion counterpart share approximately the same magnetization mode behavior. Magnonic designs aiming at synchronous or coherent tunings of spin-wave excitations at given spatially separated points within a regular square array may benefit from the new effects here described.