Macroscopic experimental validation of remagnetization dynamics in a single-domain magnetic particle

We present a macroscopic experimental platform for investigating the remagnetization dynamics of a single-domain spherical particle in a viscous medium. The particle, containing two embedded neodymium magnets, which can freely rotate within a 3D-printed shell and is subjected to a rotating magnetic field generated by orthogonal Helmholtz coils. This setup emulates the behavior of nanoscale ferromagnetic particles with finite magnetic anisotropy. We observe dynamic regimes including synchronous planar rotation, precession, and asynchronous libration, and map their transitions as functions of field frequency and amplitude. The dynamics of the particle and phase boundaries are in agreement with predictions from the nonlinear anisotropic torque model developed by Cı̄murs and Cēbers. Our findings provide a tangible and scalable experimental validation of magnetization dynamics typically constrained to the nanoscale.