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Nonlinear response of superparamagnets with finite damping: an analytical approach

J. L. Garcia-Palacios·D. A. Garanin
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Abstract

The strongly damping-dependent nonlinear dynamical response of classical superparamagnets is investigated by means of an analytical approach. Using rigorous balance equations for the spin occupation numbers a simple approximate expression is derived for the nonlinear susceptibility. The results are in good agreement with those obtained from the exact (continued-fraction) solution of the Fokker-Planck equation. The formula obtained could be of assistance in the modelling of the experimental data and the determination of the damping coefficient in superparamagnets.

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J. L. Garcia-Palacios, D. A. Garanin. 2004-04-19. Nonlinear response of superparamagnets with finite damping: an analytical approach. https://doi.org/10.1103/physrevb.70.064415

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