2.5 nm wide amorphous ferromagnetic nanocolumns were prepared by swift heavy ions irradiation of paramagnetic YCo2 thin films. The shape anisotropy-induced coercive field Hc is approximately half the anisotropy field HA- Magnetic aftereffect measurements reveal that the activation volume involved during magnetization reversal is comparable to the particle size. Given the small diameters involved, such a behaviour can be addressed either by Stoner-Wohlfarth rotation with surface perturbation or to the end-surface nucleation of a 1-D domain wall. For the later, an upper bound of the coercive field, estimated by considering a simple planar configuration, yields a reduced HC/HA ratio in agreement with the experimental value. © 1998 IEEE.
Magnetic aftereffect in quasi-ID amorphous ferromagnetic nanocolumns / Nozieres, J. P.; Givord, D.; Toussaint, J. C.; Kevorkian Laboratoire, B.; Neel, L.; Ghidini, M.; Gervais, B.. - In: IEEE TRANSACTIONS ON MAGNETICS. - ISSN 0018-9464. - 34:4(1998), pp. 991-993. [10.1109/20.706334]