Switching behavior of single nanowires inside dense nickel nanowire arrays

We report on the micromagnetic properties of highly regular hexagonal arrays of Ni nanowires, fabricated by means of electodeposition in self-ordered porous alumina. Arrays with interpore distances of 65 and 100 nm and pore diameters of 25 and 30 nm are investigated. From hysteresis loops obtained from measurements with a superconducting quantum interference device (SQUID) magnetometer, the switching field H-sw of the nanowires and its deviation DeltaH(sw) is derived. Dynamic micromagnetic modeling using the finite-element method is applied to study the reversal process in an external field. It is shown that starting at the wires' ends, the reversal occurs by means of 180degrees head-on domain walls propagating along the wire.