Dynamic stabilization of nonequilibrium domain configurations in magnetic squares with high amplitude excitations

We explore the linear and nonlinear dynamic regimes of micrometer-scale soft magnetic squares with an in-plane uniaxial anisotropy, recording the response of the magnetization in the spatial domain under a continuous sinusoidal excitation with time-resolved scanning transmission x-ray microscopy. Increasing the excitation field amplitude leads to the dynamic stabilization of nonequilibrium domain configurations, which appear at threshold amplitudes and return to the equilibrium configuration when the amplitude is reduced. On imaging the magnetization in the transition region between two stable magnetic configurations, we observe small domains originating from the vortex core. Dynamic micromagnetic simulations of the domain configuration provide qualitative agreement with the experimental data and insight into the energy dissipation and spin wave contributions.