Theory and Simulation of highly concentrated model ferrofluids in external fields

在这个项目中，我们打算通过计算机模拟和统计力学理论的分析计算来研究致密、强相互作用的铁磁流体的结构和磁性。特别是，我们将改变密度、偶极耦合、短程粒子间势、多分散性和外部外加磁场，并监测它们对结构和磁性能的影响。特别感兴趣的将是导致铁磁相和其他可能的形态相变的机制。特别是，我们将把系统限制在二维，以便尝试重现最近的强相互作用铁磁流体的实验发现，产生一个有趣的网络结构，这是密度的强函数。只要时间允许，我们还将研究动态（ac）磁化率，并试图确定粒子结合（链，球，分形簇）的可能形式，它们的弛豫时间的特征谱及其对铁磁流体宏观磁性的影响。

In this project we intend to investigate the structural and magnetic properties of dense, strongly interacting ferrofluids by means of computer simulations and analytical calculations by employing statistical mechanical theory. In particular we will vary the density, dipolar coupling, short range interparticle potential, polydispersity, and externally applied field and monitor their influence on structural and magnetic properties. Of special interest will be the mechanisms leading to the ferromagnetic phase, and other possible morphological phase transitions. In particular we will confine the system to 2D in order to try to reproduce recent experimental findings of strongly interacting ferrofluids yielding an interesting network structure, which is a strong function of density. As far as time permits we will also investigate the dynamical (ac) susceptibility and try to determine the possible forms of particles associations (chains, globules, fractal clusters), the characteristic spectrum of their relaxation times and their influence on the macroscopic magnetic properties of ferrofluids.