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arXiv · 1209.0298

Thermal fluctuations of magnetic nanoparticles

William T. Coffey·Yuri P. Kalmykov
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Abstract

The reversal time (superparamagnetic relaxation time) of the magnetization of fine single domain ferromagnetic nanoparticles owing to thermal fluctuations plays a fundamental role in information storage, paleomagnetism, biotechnology, etc. Here a comprehensive tutorial-style review of the achievements of fifty years of development and generalizations of the seminal work of Brown [W.F. Brown, Jr., Phys. Rev., 130, 1677 (1963)] on thermal fluctuations of magnetic nanoparticles is presented. Analytical as well as numerical approaches to the estimation of the damping and temperature dependence of the reversal time based on Brown's Fokker-Planck equation for the evolution of the magnetic moment orientations on the surface of the unit sphere are critically discussed while the most promising directions for future research are emphasized.

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William T. Coffey, Yuri P. Kalmykov. 2014-04-03. Thermal fluctuations of magnetic nanoparticles. https://doi.org/10.1063/1.4754272

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