Reconfigurable 3D magnonic crystal: tunable and localized spin-wave excitations in CoFeB meander-shaped film

TL;DR

This paper investigates tunable and localized spin-wave excitations in a reconfigurable 3D magnonic crystal made of CoFeB meander-shaped films, combining experimental measurements and micromagnetic simulations.

Contribution

It introduces a novel 3D magnonic crystal structure with tunable spin-wave properties and demonstrates control over spin-wave modes via magnetic field orientation.

Findings

Vertical segments induce easy-axis magnetic anisotropy.

Spin-wave modes can be tuned by magnetic field direction.

Potential applications in tunable metasurfaces and magnetic memories.

Abstract

In this work, we study experimentally by broadband ferromagnetic resonance measurements, the dependence of the spin-wave excitation spectra on the magnetic applied field in CoFeB meander-shaped films. Two different orientations of the external magnetic field were explored, namely parallel or perpendicular to the lattice cores. The interpretation of the field dependence of the frequency and spatial profiles of major spin-wave modes were obtained by micromagnetic simulations. We show that the vertical segments lead to the easy-axis type of magnetic anisotropy and support the in-phase and out-of-phase spin-wave precession amplitude in the vertical segments. The latter could potentially be used for the design of tunable metasurfaces or in magnetic memories based on meandering 3D magnetic films.