Effect of the shape anisotropy and configurational anisotropy on the magnetic structure of ferromagnetic nanodots

Processes of magnetization reversal of ordered square arrays of “nanodots” of different geometry coupled by dipole-dipole interaction that were formed by a focused beam of Ga+ ions from continuous polycrystalline Co films have been investigated. It has been established that the magnetic structure upon the magnetization reversal is mainly determined by the shape anisotropy of the nanodots. The round and square nanodots undergo magnetization reversal via a magnetic vortex, whereas the rectangular nanodots demonstrate a finite set of single-domain states depending on the orientations of the external magnetic field and easy axis of magnetization. It has been shown that the magnitude of the switching field of arrays of round and square nanodots and the distribution of switching fields in the system of rectangular nanodots upon magnetization reversal along the easy axis is substantially affected by the configurational anisotropy.