Production of magnetic nano wires by electrodeposition technique and their properties

The production of materials as small as possible has become inevitable with developing technology. Therefore, the production of nano-sized materials has been created many new areas and the nano concept has entered almost every field of science.Electrodeposited 3d transition metal alloys such as nickel, cobalt and iron are of interest for their unique magnetic and thermo-physical properties. They have been used for recording, memory, storage devices and sensor applications.In this thesis, first, the anodic aluminum oxide (AAO) templates were prepared by the conventional two-step anodic oxidation procedure. Different times of anodic oxidation and wet etching were investigated to find conditions suitable for the production of ordered high-density nanopores of various diameters (30-200nm).Second, NiFe and CoNiFe nanowires and nanotubes were grown into highly ordered AAO templates by dc electrodeposition method. The effect of electrochemical bath parameters (pH, deposition potential, deposition time) to magnetic and morphological properties of nanostructures were investigated. Voltammetric and potentiostatic results indicate that the back electrodes placed on AAO play the main role in obtaining nanowire or nanotube structured materials.Electrochemical nucleation and growth mechanism of nanostructures on AAO were discussed on the basis of Scharifker-Hills model.The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) images showed that nanowires/nanotubes are almost parallel and their diameter and lengths are around 200-300nm, 5-25µm, respectively. Magnetization curves showed that the easy axis of magnetization of these samples is close to the long axis of the nanotube or nanowire.Keywords: NiFe, CoNiFe, nanopore, AAO, nanowire, nanotube, electrodeposition, magnetic.