Creation of Out-of-Plane Magnetization Ordering by Increasing the Repetitions Number $N$ in (Co/Au) $_{\rm N}$ Multilayers

The influence of the Co layer thickness as well as the number of repetitions N on the magnetic properties of (Co/Au)_N multilayers was investigated systematically using magneto-optical techniques, vibrating sample magnetometry, and magnetic force microscopy. The studies focused on the characteristics of magnetic hysteresis loops in connection with magnetic domain structure parameters. Increasing the repetitions number, an out-of-plane magnetization ordering is created for Co layers with a thickness larger than the single-layer thickness at which the spin reorientation transition occurs.