Magnetic microstructure of the spin reorientation transition: A computer experiment

The scenario of the spin reorientation in two-dimensional films within firs t-order anisotropy approximation is theoretically studied by means of Monte Carlo simulations. The magnetic microstructure is investigated as a functi on of the ratio of the perpendicular anisotropy energy to the dipolar one. If the anisotropy dominates, out-of-plane domains will be found while in-pl ane vortices appear for a vanishing anisotropy. In the range of comparable anisotropy and dipolar energies a complex domain pattern evolves yielding a continuous transition between the two structures. The structure with equal ly distributed magnetic moment orientation is stable at the point where ani sotropy and dipolar energies cancel each other.