Nonlinear Behavior of Magnetic Fluid in Brownian Relaxation: Numerical Simulation and Derivation of Empirical Model

  • Takashi YoshidaEmail author
  • Keiji Enpuku
Part of the Springer Proceedings in Physics book series (SPPHY, volume 140)


Nonlinear Brownian relaxation of magnetic fluids for the case of large excitation field was studied in relation to its biomedical applications. The Fokker-Planck equation, which describes the nonlinear behavior of magnetic fluids, was solved by numerical simulation when ac field was applied. Frequency-dependences of the harmonics were investigated in terms of the effective Brownian relaxation time τ eff, which was empirically obtained from the ac susceptibility of the fundamental component. It was shown that higher harmonics become small even at ωτ eff=1 compared to each quasi-static harmonics amplitudes.


Frequency Dependence Nonlinear Behavior Magnetic Fluid High Harmonic Nonlinear Property 
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Copyright information

© Springer-Verlag GmbH Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Department of Electrical EngineeringKyushu UniversityNishi-kuJapan

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