Fabrication Of Ordered Nanoarrays By Electroless Deposition And Their Properties

In this paper, porous alumina membrane was prepared by two-step anodic oxidation in oxalic acid electrolyte. Ni-P and Cu nanowire arrays and nanotube arrays were fabricated by electroless deposition using porous alumina membrane. Transmission electron microscope and X-ray diffraction are employed to study the morphology, structure and growing mechanism of Ni-P, Cu nanowires and nanotubes. The results show that the apertures have the same diameter. The holes are parallel to each other and perpendicular to the membrane surface. The distribution of holes with perfect circular shape is in highly hexagonal order in several microns. The fabricated Ni-P nanowires have high aspect ratio. The diameter of nanowires depends on the caliber of holes in alumina template, and the length of nanowires depends on thickness of the template. The inner diameter of Ni-P nanotubes prepared at room temperature is uniform and is independent of depositing time. The structures of both Ni-P nanowires and nanotubes are amorphous. With the depositing time lasting, the inner diameter of Cu nanotubes is decreasing. The Cu nanotubes will finally become nanowires as time goes on. The structures of Cu ordered nanoarrays are amorphous too, and haven't obvious preferred orientation.Vibrating sample meter and spectrometer are employed to study the hysteresis loops of Ni-P nanowire ordered arrays and light absorption of nano Cu particle/Al₂O₃ assembled system, respectively. The results indicate that Ni-P nanowire ordered array has sharp perpendicular magnetic anisotropy, which depends on the shape anisotropy. There is only one border of absorption band in the absorbance spectra for nano Cu particle/ Al₂O₃ assembled system. The ambiplasma formant disappears.