Effects of antidot shape on the spin wave spectra of two-dimensional Ni80Fe20 antidot lattices

Abstract

We show that the optically induced spin wave spectra of nanoscale Ni80Fe20 (permalloy) antidot lattices can be tuned by changing the antidot shape. The spin wave spectra also show an anisotropy with the variation of the in-plane bias field orientation. Analyses show this is due to various quantized and extended modes, whose nature changes with the antidot shape and bias field orientation as a result of the variation of the internal magnetic field profile. The observed variation and anisotropy in the spin waves with the internal and external parameters are important for their applications in magnonic devices.

Tunable Magnetization Dynamics in Interfacially Modified Ni81Fe19/Pt Bilayer Thin Film Microstructures

“…On the other hand, for data storage and memory devices higher damping aids suppression of the magnetization precession during writing. Currently, to achieve control over spin waves 4 lithographic patterning of magnonic crystals 5 6 7 8 was introduced, while for magnetic domain wall devices the behavior has been controlled by the lithographically defined shape 9 of nanowire structures and anisotropy 10 has been introduced by patterning magnetic films. Such patterning requires complicated nanofabrication methods, which, on a smaller scale may introduce defects that significantly affect the magnetic behaviour.…”

Tunability of Domain Structure and Magnonic Spectra in Antidot Arrays of Heusler Alloy

“…Previous reports on such structures have considered zero magnetocrystalline anisotropy for the constituent films. [31,32] However, in our study both cubic and uniaxial anisotropies along with the shape anisotropy play important roles in determining the total anisotropy in the antidot samples. In CA and SA, the symmetric structure of the holes does not lead to any additional shape anisotropy along with the anisotropy of the parent thin film.…”

“…The remarkable difference in the mode profile between the different antidots arises due to the difference in their internal field distribution which leads to formation of extended and localized modes. [31] Additionally, asymmetry introduced from the fabrication process imposes further differences in the internal field profiles in the antidot arrays. Nevertheless, we have tried to address this issue by considering roundish edges during simulations (see insets of figure 4 (f) -(h)) for square, triangular, and diamond shaped antidots (SA, TA, and DA).…”

“…In addition, there are few reports on antidot arrays with the anisotropic structures like triangular and diamond shaped holes which may significantly modify the internal field distribution in the vicinity of the holes leading to further modifications of the SW spectra of such systems. [16,31,32] In this present work we have chosen Co 2 Fe 0.4 Mn 0.6 Si (CFMS) thin films and their antidot arrays for the investigation of SW dynamics. To the best of our knowledge, there are no reports yet for the study of magnetization dynamics in antidot arrays of similar materials.…”

Spin-wave dynamics in permalloy/cobalt magnonic crystals in the presence of a nonmagnetic spacer

“…Changes of dot or antidot shape, their rotation with respect to the crystallographic axes, imperfections in their shape or at their edges can further modify SW spectra 35,36,37 . Thus, the large variety of shapes for dots or antidots and of their arrangements together with magnetic configurations which can be realized in MCs 38,39,40,41 , makes magnonics an inexhaustible and intriguing topic of research. More specifically, no enough attention has been given to the study of collective dynamics in bi-component MCs where a non-magnetic spacer separates the two magnetic materials.…”