Controlling spin textures of magnetic nanodots using an antidot matrix

We present a study of the magnetic properties of circular nanodots placed inside or in the vicinity of a circular hole in the perpendicularly magnetized antidot matrix. Micromagnetic simulations were performed to investigate the remanent magnetization configurations of the nanodots as a function of their vertical position relative to the matrix. The results demonstrate that the strength of the radial component of antidot matrix stray fields varies significantly along the vertical coordinate. This change influences the remanent state of nanodots, leading, depending on their location, to the stabilization of several magnetization configurations: radial vortex, curled vortex, or single-domain state. It was found that placing the dot at few nanometers below or above the matrix allows to stabilize the vortex state for a nanodot with the smallest diameter. This result provides a hint to tailor the magnetic properties of nanodots for their applications in spintronic and magnonic devices.