Toussaint Renaud, Helgesen Geir, Flekkøy Eirik G
Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway.
Phys Rev Lett. 2004 Sep 3;93(10):108304. doi: 10.1103/PhysRevLett.93.108304. Epub 2004 Sep 2.
Nonmagnetic particles in a carrier ferrofluid acquire an effective dipolar moment when placed in an external magnetic field. This fact leads them to form chains that will roughen due to Brownian motion when the magnetic field is decreased. We study this process through experiments, theory and simulations, three methods that agree on the scaling behavior over 5 orders of magnitude. The rms width goes initially as t(1/2), then as t(1/4) before it saturates. We show how these results complement existing results on polymer chains, and how the chain dynamics may be described by a recent non-Markovian formulation of anomalous diffusion.
当置于外部磁场中时，载体铁磁流体中的非磁性粒子会获得有效偶极矩。这一事实导致它们形成链条，当磁场减弱时，这些链条会因布朗运动而变得粗糙。我们通过实验、理论和模拟这三种方法来研究这一过程，这三种方法在超过5个数量级的标度行为上是一致的。均方根宽度最初随时间的1/2次方变化，然后随时间的1/4次方变化，直至饱和。我们展示了这些结果如何补充聚合物链的现有结果，以及如何用最近的反常扩散非马尔可夫公式来描述链动力学。
