Effect of annealing on nanostructured Fe networks

Abstract

Contiguous nanostructured Fe network structures sputter deposited on a porous template (nanochannel alumina) have been shown to have a high coercivity due to shape anisotropy. When these networks are vacuum annealed, even at modest temperatures, there is a significant improvement in their in-plane coercivities. The shape of the annealed coercivity vs. thickness plot is a function of the substrate geometry. The maximum coercivity obtained through annealing is /spl sim/1390 Oe and appears to be an absolute maximum. The topology of these networks when viewed by a scanning electron microscope undergoes morphological changes perpendicular to the plane of the network upon annealing. The annealed structures have the appearance of a modified "chain of spheres", or a mesh of spheres.