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arXiv · 1501.01171

Sensing magnetic nanoparticles using nano-confined ferromagnetic resonances in a magnonic crystal

Peter Metaxas·Manu Sushruth·Ryan Begley·Junjia Ding·Robert Woodward·Ivan Maksymov·Maximilian Albert·Weiwei Wang·Hans Fangohr·Adekunle Adeyeye·Mikhail Kostylev
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Abstract

We demonstrate the use of the magnetic-field-dependence of highly spatially confined, GHz-frequency ferromagnetic resonances in a ferromagnetic nanostructure for the detection of adsorbed magnetic nanoparticles. This is achieved in a large area magnonic crystal consisting of a thin ferromagnetic film containing a periodic array of closely spaced, nano-scale anti-dots. Stray fields from nanoparticles within the anti-dots modify resonant dynamic magnetisation modes in the surrounding magnonic crystal, generating easily measurable resonance peak shifts. The shifts are comparable to the resonance linewidths for high anti-dot filling fractions with their signs and magnitudes dependent upon the modes' localisations (in agreement with micromagnetic simulation results). This is a highly encouraging result for the development of frequency-based nanoparticle detectors for high speed nano-scale biosensing.

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Peter Metaxas, Manu Sushruth, Ryan Begley, Junjia Ding, Robert Woodward, Ivan Maksymov, Maximilian Albert, Weiwei Wang, Hans Fangohr, Adekunle Adeyeye, Mikhail Kostylev. 2015-01-06. Sensing magnetic nanoparticles using nano-confined ferromagnetic resonances in a magnonic crystal. https://doi.org/10.1063/1.4922392

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