Velocity statistics of dynamic spinners in out-of-equilibrium magnetic suspensions

Alexey Snezhko, Igor Aronson

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We report on the velocity statistics of an out-of-equilibrium magnetic suspension in a spinner phase confined at a liquid interface. The suspension is energized by a uniaxial alternating magnetic field applied parallel to the interface. In a certain range of the magnetic field parameters the system spontaneously undergoes a transition into a dynamic spinner phase (ensemble of hydrodynamically coupled magnetic micro-rotors) comprised of two subsystems: self-assembled spinning chains and a gas of rotating single particles. Both subsystems coexist in a dynamic equilibrium via continuous exchange of the particles. Spinners excite surface flows that significantly increase particle velocity correlations in the system. For both subsystems the velocity distributions are strongly non-Maxwellian with nearly exponential high-energy tails, P(v) ∼ exp(-v/v0). The kurtosis, the measure of the deviation from the Gaussian statistics, is influenced by the frequency of the external magnetic field. We show that in the single-particle gas the dissipation is mostly collisional, whereas the viscous damping dominates over collisional dissipation for the self-assembled spinners. The dissipation increases with the frequency of the applied magnetic field. Our results provide insights into non-trivial dissipation mechanisms determining self-assembly processes in out-of-equilibrium magnetic suspensions.

Original languageEnglish (US)
Pages (from-to)6055-6061
Number of pages7
JournalSoft Matter
Volume11
Issue number30
DOIs
StatePublished - Aug 14 2015

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spinners
magnetic suspension
Suspensions
dissipation
Statistics
statistics
Magnetic fields
magnetic fields
Gases
viscous damping
kurtosis
Velocity distribution
gases
Self assembly
metal spinning
rotors
self assembly
Rotors
velocity distribution
Damping

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics

Cite this

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abstract = "We report on the velocity statistics of an out-of-equilibrium magnetic suspension in a spinner phase confined at a liquid interface. The suspension is energized by a uniaxial alternating magnetic field applied parallel to the interface. In a certain range of the magnetic field parameters the system spontaneously undergoes a transition into a dynamic spinner phase (ensemble of hydrodynamically coupled magnetic micro-rotors) comprised of two subsystems: self-assembled spinning chains and a gas of rotating single particles. Both subsystems coexist in a dynamic equilibrium via continuous exchange of the particles. Spinners excite surface flows that significantly increase particle velocity correlations in the system. For both subsystems the velocity distributions are strongly non-Maxwellian with nearly exponential high-energy tails, P(v) ∼ exp(-v/v0). The kurtosis, the measure of the deviation from the Gaussian statistics, is influenced by the frequency of the external magnetic field. We show that in the single-particle gas the dissipation is mostly collisional, whereas the viscous damping dominates over collisional dissipation for the self-assembled spinners. The dissipation increases with the frequency of the applied magnetic field. Our results provide insights into non-trivial dissipation mechanisms determining self-assembly processes in out-of-equilibrium magnetic suspensions.",
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Velocity statistics of dynamic spinners in out-of-equilibrium magnetic suspensions. / Snezhko, Alexey; Aronson, Igor.

In: Soft Matter, Vol. 11, No. 30, 14.08.2015, p. 6055-6061.

Research output: Contribution to journalArticle

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