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Tuning Mie scattering resonances in soft materials with magnetic fields
Thomas Brunet1, Kevin Zimny2, Benoit Mascaro1
1Université de Bordeaux, CNRS, UMR 5295, Institut de Mécanique et d'Ingénierie, 351 cours de la Libération, 33405 Talence, France.
Physical Review Letters
|February 4, 2014
Summary
Researchers demonstrate a novel method to tune Mie scattering resonances in random media using low-induction magnetic fields. This technique, applicable to both electromagnetic and acoustic waves, allows for a fivefold variation in acoustic attenuation.
Area of Science:
- Acoustics and Optics
- Materials Science
- Fluid Dynamics
Background:
- Mie scattering resonances in random media are crucial for wave propagation.
- Controlling these resonances typically requires physical alteration of the medium.
- External fields offer a non-invasive tuning method.
Purpose of the Study:
- To propose and demonstrate a novel method for reversibly tuning Mie scattering resonances.
- To investigate the effect of magnetic fields on the acoustic properties of ferrofluid emulsions.
- To establish a tunable acoustic attenuation in disordered media.
Main Methods:
- Utilized low induction magnetic fields to alter droplet morphology in ferrofluid emulsions.
- Performed ultrasound experiments on spherical droplets dispersed in a Bingham fluid.
- Measured changes in effective acoustic attenuation coefficient based on magnetic field parameters.
Main Results:
- Demonstrated reversible tuning of Mie scattering resonances via magnetic fields.
- Observed a fivefold variation in effective acoustic attenuation coefficient.
- Showed that magnetic-field-induced prolate spheroid formation significantly impacts acoustic properties.
Conclusions:
- External magnetic fields provide an effective means to tune Mie scattering resonances in random media.
- The proposed method offers a controllable way to adjust acoustic attenuation in disordered materials.
- This approach has potential applications in tunable acoustic and electromagnetic devices.
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