Regime change in the aggregate structure of magnetic disk-like particles in a quasi-2D suspension system via multi-particle collision dynamics simulations

We have addressed the problem of controlling a regime change in a quasi-2D system of magnetic disk-like particles by means of the strength and direction of an applied magnetic field. In the present study, two typical directions have been addressed, i.e. a y-direction field parallel to the 2D plane and a z-direction field normal to that plane of the particle disk. It is shown that the direction of an applied magnetic field is a significant factor in particle aggregation and can give rise to different regime changes. That is, an applied magnetic field parallel to the 2D system plane functions to induce a regime change in the aggregate structure from linear column-like particle clusters into a knitting-pattern formation, whereas in the case of an applied field normal to the 2D plane, a regime of long column-like clusters transforms into a particle distribution with no discernible internal structure. Key points of the present paper:The direction of an applied magnetic field may give rise to significantly different regime changes in particle aggregation.An applied magnetic field parallel to the 2D system plane induces a regime change from long linear column-like clusters into a knitting-pattern formation.A magnetic field in a direction normal to the 2D plane induces a regime change from long linear column-like clusters into a regime with no discernible internal structure.The strength and the direction of an applied magnetic field is a feasible tool for controlling a regime change in the aggregate structure. The direction of an applied magnetic field may give rise to significantly different regime changes in particle aggregation. An applied magnetic field parallel to the 2D system plane induces a regime change from long linear column-like clusters into a knitting-pattern formation. A magnetic field in a direction normal to the 2D plane induces a regime change from long linear column-like clusters into a regime with no discernible internal structure. The strength and the direction of an applied magnetic field is a feasible tool for controlling a regime change in the aggregate structure.