Non-collinear magnetic states in Ni-Fe/Au/Co/Au multilayers investigated by magnetoresistance measurements

Sputtered Ni 80 Fe 20 /Au/Co/Au multilayers (MLs) exhibit perpendicular anisotropy of Co layers and easy-plane anisotropy of Permalloy layers. In these samples the changes of relative orientation of magnetization between Co and NiFe layers, with magnetic field, can be determined by magnetoresistance measurements. The magnetic structure is discussed for two types of Ni 80 Fe 20 /Au/Co/Au MLs characterized by a weak coupling between ferromagnetic layers: (i) MLs with rectangular hysteresis loops and small coercive field, (ii) MLs with dense stripe domain structure in Co layers.