We experimentally investigate cluster structures formed by paramagnetic particles in a thin magnetorheological (MR) fluid layer, the thickness of which normalized by the particle diameter ranges from 3.8 to 31, under a dc magnetic field perpendicular to the fluid layer. We particularly focus on cluster structures formed in a dc magnetic field of high ramping rates, in which case the structures may be greatly different from those formed under equilibrium conditions. When a dc magnetic field is applied so rapidly, paramagnetic particles form chain clusters along the field direction as expected, but some chain clusters coalesce in the lateral direction to form bent-wall structures. We analyze the dependence of cluster structures on experimental parameters such as the thickness of the MR fluid layer and the intensity of the magnetic field.

中文翻译：

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在直流磁场作用下的薄磁流变液层中形成的非平衡簇结构

我们实验研究了在垂直于流体层的直流磁场下，由顺磁性粒子在薄磁流变（MR）流体层中形成的团簇结构，其厚度通过粒径归一化为3.8到31。我们特别关注在高斜率的直流磁场中形成的簇结构，在这种情况下，该结构可能与在平衡条件下形成的簇结构大不相同。当如此迅速地施加直流磁场时，顺磁性粒子会按预期的那样沿磁场方向形成链簇，但是一些链簇在横向会聚在一起，从而形成弯壁结构。我们分析了簇结构对实验参数（如MR流体层的厚度和磁场强度）的依赖性。