MAGNETIC-PROPERTIES OF ELECTRODEPOSITED NANOWIRES

Electrodeposited multilayered nanowires grown within a polycarbonate m embrane constitute a new medium in which giant magnetoresistance (GMR) perpendicular to the plane of the multilayers can be measured. These structures can exhibit a perpendicular GMR of at least 22% at ambient temperature. We performed detailed studies both of reversible magnetiz ation and of irreversible remanent magnetization curves for CoNiCu/Cu/ CoNiCu multilayered and CoNiCu pulse-deposited nanowire systems with C o:Ni ratios of 6:4 and 7:3 respectively in the range 10-290 K, allowin g the magnetic phases of these structures to be identified. Shape anis otropy in the pulse-deposited nanowire and inter-layer coupling in the multilayered nanowire are shown to make important contributions to th e magnetic properties. Dipolar-like interactions are found to predomin ate in both nanowire systems. Magnetic force microscope (MFM) images o f individual multilayered nanowires exhibit a contrast consistent with there being a soft magnetization parallel to the layers. Switching of the magnetic layers in the multilayered structure into the direction of the MFM tip's stray field is observed.