Thermodiffusion in ferrofluids regarding thermomagnetic convection

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• 作者：Lisa Sprenger ; ^{Lisa.Sprenger@tu-dresden.de} ; Adrian Lange ; Stefan Odenbach
• 关键词：Ferrofluids ; Magnetic fluids ; Rayleigh number ; Soret coefficient ; Thermodiffusion ; Thermomagnetic convection
• 刊名：Comptes Rendus Mecanique
• 出版年：2013
• 出版时间：April-May, 2013
• 年：2013
• 卷：341
• 期：4-5
• 页码：429-437
• 全文大小：740 K

文摘

Magnetic fluids, also called ferrofluids, are binary liquids consisting of magnetic nanoparticles being dispersed in a carrier liquid. They show very strong thermodiffusive behaviour with a Soret coefficient () of approximately without a magnetic field. The dependence of the Soret coefficient on a magnetic field can lead to even higher values, and to a change in the coefficient?s sign. This change in the direction of movement of the nanoparticles strongly affects the onset of thermomagnetic convection. A linear stability analysis reveals that thermodiffusion with a positive sign of the Soret coefficient enhances the onset of convection, whereas negative coefficients starting at about suppress convection at all.