Broad-band FMR study of ferromagnetic thin films patterned with antidot lattices

• Published in: Physica. C, Superconductivity Superconductivity, 2012-09, Vol.479, p.83-87
• Main Authors: Bhat, V., Woods, J., De Long, L.E., Hastings, J.T., Metlushko, V.V., Rivkin, K., Heinonen, O., Sklenar, J., Ketterson, J.B.
• Format: Article
• Language: English
• Subjects: Antidots; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain wall pinning; Exact sciences and technology; Ferromagnetic antidot arrays; Ferromagnetic resonance; Ferromagnetic vortices; Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance; Fluid flow; Hysteresis; Lattices; Magnetic fields; Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Micromagnetic simulations; Physics; Separation; Texture; Thin films
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2012.02.003

Previous ferromagnetic resonance (FMR) studies of ferromagnetic (FM) thin films patterned with antidot (AD) arrays have generally avoided the low-field, hysteretic regime that is dominated by irreversible domain wall (DW) dynamics in unpatterned films. Moreover, FM vortices have not yet been identified and systematically studied in films patterned with AD lattices (ADLs). We have studied DC magnetization and broad-band FMR data for permalloy thin films of thickness t≈25nm, patterned with square lattices of square-shaped AD of width D and separation d=1000nm. We observe highly reproducible magnetic hysteresis curves and FMR spectra in the low-field reversal regime (i.e., applied magnetic fields H