Stability of nontrivial magnetic structures in ferromagnetic films with antidots

Abstract

The paper investigates stability conditions of vortex-like inhomogeneities in perforated ferromagnet films with strong uniaxial anisotropy of the ‘easy plane’ type. It has been demonstrated that the non-trivial magnetic structures, which are characterized by the absence of an exit of the magnetization vector from the film’s plane, can be observed at the absolute values of the anisotropy constant which exceed a certain threshold point. Possible methods (analytical, numeric, and empiric) have been developed to calculate this threshold value. Universally applicable estimates have been obtained of the minimum permissible value of the anisotropy constant for a number of the most important cases. Possible scenarios have been investigated for a loss of stability of the magnetic structure as the film’s material parameters vary.