Magnetic microstructure of the spin reorientation transition.

The scenario of the magnetization reorientation in second-order perpendicular anisotropy approximation is theoretically studied by means of Monte-Carlo simulations. The microstructure is investigated as a function of the difference between first-order anisotropy and demagnetizing energy K[sub eff]=K[sub 1]-E[sub D] and the second-order anisotropy K[sub 2]. An influence of the second-order perpendicular anisotropy on the spin reorientation transition is found when K[sub eff] vanishes. The broadening and coalescing of domain walls found earlier for K[sub 2]=0 is prevented by positive K[sub 2]. The domain wall width and energy are determined by K[sub 2]. For K[sub 2]>0 the transition via a canted vortex-like structure is found which yields the smooth, continuous connection between the vertical domain structure and the vortex structure with in-plane magnetization. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]