Simulation of spin reorientation in cubic ferromagnets with defects

Nucleation processes in spin-reorientation phase transitions in real magnets are studied theoretically. The magnetization distribution corresponding to zero-degree domain wall forms the basis of the model representation of nuclei of the new phase, which are pinned at detects. As a result of numerical implementation of the corresponding variational problem for a finite-thickness plate, stable states of such magnetic inhomogeneities are determined and it is shown that their structure and properties are mainly controlled by parameters of a defect and the Q factor of the sample. The dependences obtained in this way make it possible to describe the behavior of new-phase nuclei in the vicinity of the spin-reorientation phase transition, which is in qualitative agreement with experimental data.