Magnetization processes in narrow and wide cross-shaped Co/Cu/NiFe wires

Wide and narrow cross-shaped wires in the Co/Cu/NiFe trilayer structures we re fabricated by using electron-beam lithography, and the magnetization pro cesses were investigated by measuring magnetoresistance (MR) and Hall resis tance (HR). The MRs of both the wide and narrow wires showed two values cor responding to the parallel and antiparallel configurations because of the g iant MR effects. The observed HR in the wide cross-shaped wire was understo od by the magnetization processes in which the magnetizations in the NiFe a nd Co layers rotate in the same direction. However, the observed HR in the narrow cross-shaped wire indicates that the magnetizations in the NiFe and Co layers rotated in opposite directions. Such magnetization behaviors are explained by considering the dipole interaction between the NiFe and Co lay ers.