Spatially resolved GHz magnetization dynamics of a magnetite nano-particle chain inside a magnetotactic bacterium

Understanding magnonic properties of nonperiodic magnetic nanostructures requires real-space imaging of ferromagnetic resonance modes with spatial resolution well below the optical diffraction limit and sampling rates in the 5–100 GHz range. Here, we demonstrate element-specific scanning transmissio...

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Bibliographic Details
Main Authors: Thomas Feggeler, Ralf Meckenstock, Detlef Spoddig, Benjamin W. Zingsem, Hendrik Ohldag, Heiko Wende, Michael Farle, Michael Winklhofer, Katharina J. Ollefs
Format: Article
Language:English
Published: American Physical Society 2021-07-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.3.033036
Description
Summary:Understanding magnonic properties of nonperiodic magnetic nanostructures requires real-space imaging of ferromagnetic resonance modes with spatial resolution well below the optical diffraction limit and sampling rates in the 5–100 GHz range. Here, we demonstrate element-specific scanning transmission x-ray microscopy-detected ferromagnetic resonance (STXM-FMR) applied to a chain of dipolarly coupled Fe_{3}O_{4} nano-particles (40–50 nm particle size) inside a single cell of a magnetotactic bacterium Magnetospirillum magnetotacticum. The ferromagnetic resonance mode of the nano-particle chain driven at 6.748 GHz and probed with 50 nm x-ray focus size was found to have a uniform phase response but non-uniform amplitude response along the chain segments due to the superposition of dipolar coupled modes of chain segments and individual particles, in agreement with micromagnetic simulations.
ISSN:2643-1564