Magnetization reversal of Fe/Gd multilayers on self-assembled arrays of nanospheres

Magnetization reversal of Fe/Gd multilayers deposited on self-assembled silica nanospheres has been studied by scanning transmission x-ray microscopy. Both the microscopic magnetic behavior and the macroscopic hysteresis loop can be changed drastically by varying the diameter of the spheres or the number of bilayers of the deposited system. In both cases the observed changes are attributed to a transition from a radial to a uniaxial distribution of the magnetic moments, however, with different underlying mechanisms.