Synthetic control of large-area, ordered Fe nanotubes and their nanotube-core/alumina-sheath nanocables

Fe nanotubes with different outer diameters (55 nm, 80 nm, 200 nm) have been successfully fabricated into the anodic alumina membranes (AAMs) by direct-current electrochemical deposition technique, and their nanotube-core/alumina-sheath nanocables were further realized with a simple chemical etching method. X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses show that the Fe nanotube core is single crystalline along [110] crystal direction, and the sheath is an amorphous alumina. Such a new nanostructure may be suitable for two-dimensional ferromagnetic structural materials and the diameter of the nanocables can be modulated by controlling the experimental conditions, and the formation mechanism was explored. Our experimental results provide a useful way for fabricating low-cost and large-scale metal nanocables, which are of important applications in modern nanoelectronics.