Behavior of magnetic particles under fluctuating fields considering hysteresis characteristics

Abstract

Simulations of magnetic particles are mostly carried out under spatially and temporally static magnetic fields. It is well known that chain-like clusters are formed under these constant fields. However the hysteresis characteristics of particles are therefore often neglected. In this paper, methods to analyze behavior of magnetic particles with hysteresis characteristics under fluctuating fields are proposed. Consideration of hysteresis characteristics and fluctuating fields brings nonlinearity and driving forces to the system in addition to the energy dissipation caused by particle collisions. This research aims to find the foothold of chaotic behavior, which is often found in these systems, among particle clustering. The proposed methods start from the discretization of fields. Collisions and clustering are modeled by treating mechanical contacts, namely, by solving Hertz's contact problem. A symplectic integrator is used for time integration. For the simulation, behavior of 200 magnetic particles under spatially and temporally fluctuating fields were examined. The results imply hysteresis characteristics have a great effect on clustering patterns.