Open AccessFerromagnetic resonance in a topographically modulated permalloy film
Author(s) -
Joseph Sklenar,
Phillip Tucciarone,
R. J. Lee,
Daniel B. Tice,
Robert P. H. Chang,
S. J. Lee,
I. P. Nevirkovets,
Olle Hein,
J. B. Ketterson
Publication year - 2015
Publication title -
physical review. b, condensed matter and materials physics
Language(s) - English
Resource type - Journals
eISSN - 1538-4489
pISSN - 1098-0121
DOI - 10.1103/physrevb.91.134424
Subject(s) - permalloy , ferromagnetic resonance , condensed matter physics , materials science , magnonics , ferromagnetism , resonance (particle physics) , thin film , micromagnetics , spin wave , crystal (programming language) , optics , magnetic field , magnetization , physics , nanotechnology , spin polarization , atomic physics , quantum mechanics , spin hall effect , electron , computer science , programming language
A major focus within the field of magnonics involves the manipulation and control of spin-wave modes. This is usually done by patterning continuous soft magnetic films. Here, we report on work in which we use topographic modifications of a continuous magnetic thin film, rather than lithographic patterning techniques, to modify the ferromagnetic resonance spectrum. To demonstrate this technique we have performed in-plane, broadband, ferromagnetic resonance studies on a 100-nm-thick permalloy film sputtered onto a colloidal crystal with individual sphere diameters of 200 nm. Effects resulting from the, ideally, sixfold-symmetric underlying colloidal crystal were studied as a function of the in-plane field angle through experiment and micromagnetic modeling. Experimentally, we find two primary modes; the ratio of the intensities of these two modes exhibits a sixfold dependence. Detailed micromagnetic modeling shows that both modes are quasiuniform and nodeless in the unit cell but that they reside in different demagnetized regions of the unit cell. Our results demonstrate that topographic modification of magnetic thin films opens additional directions for manipulating ferromagnetic resonant excitations.The experimental work received support by the Air Force Office of Scientific Research and utilized facilities maintained by the supported Northwestern Materials Research Center supported by the National Science Foundation under Contract No. DMR-1121262; it was equally supported by the National Science Foundation under NSF Award No. EEC-1062784. We would like to thank Varada Bal for her assistance in obtaining AFM images. Work by O.H. was supported by the Department of Energy, Office of Science, Basic Energy Sciences, Division of Materials Science and Engineering. We gratefully acknowledge the computing resources provided on Blues, the high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the National Science Foundation