Faculty of Physics, Boltzmanngasse 5, University of Vienna, Vienna, Austria.
Nanoscale. 2017 May 18;9(19):6448-6462. doi: 10.1039/c7nr01245d.
Systems whose magnetic response can be finely tuned using control parameters, such as temperature and external magnetic field strength, are extremely desirable, functional materials. Magnetic nanoparticles, in particular suspensions thereof, offer opportunities for this controllability to be realised. Cube-like particles are particularly mono-disperse examples that, together with their favourable packing behaviour, make them of significant interest for study. Using a combination of analytical calculations and molecular dynamics we have studied the self-assembly of permanently magnetised dipolar superballs. The superball shape parameter was varied in order to interpolate the region between the already well-studied sphere system and that of the recently investigated cube. Our findings show that as a superball particle becomes more cubic the chain to ring transition, observed in the ground state of spherical particles, occurs at an increasingly larger cluster size. This effect is mitigated, however, by the appearance of a competing configuration; asymmetric rings, a conformation that we show superballs can readily adopt.
系统的磁响应可以通过控制参数（如温度和外磁场强度）进行精细调节，是非常理想的功能材料。磁性纳米粒子，特别是它们的悬浮液，为实现这种可控性提供了机会。立方体形的粒子是特别单分散的例子，它们的有利堆积行为使它们成为研究的重要对象。我们使用分析计算和分子动力学的组合，研究了永久磁化偶极超球的自组装。为了在已经研究得很好的球体系统和最近研究的立方体系统之间进行插值，我们改变了超球形状参数。我们的研究结果表明，随着超球粒子变得更加立方体状，在球体粒子的基态中观察到的链到环的转变，在越来越大的团簇尺寸下发生。然而，这种效应被一种竞争构型所缓解；非对称环，我们表明超球很容易采用的一种构象。
