Electrochemical Preparation And Magnetism Of Multilayered Nanowires

The purposes of this dissertation are to study the electrochemical preparation, characterization of aluminum anodic oxide membrane (AAO), nanowire arrays, multilayered nanowire arrays and their properties. By utilizing electrochemical techniques and modern physical methods, the influencing factors, electrodeposition mechanism and related properties were investigated. The research contents and the gained chief achievements are as follows: First of all, aluminum anodic oxide membranes (AAO) were formed in H2SO4,H2C2O4 and H3PO4 electrolytes. Highly ordered AAOs were formed by a two–step anodizing process in H2SO4 and H2C2O4.The membranes were observed by scan electron microscopy (SEM) and atomic force micrograph (AFM). The conditions of anodizing such as acid solution, annealing, applied voltage, anodizing time, temperature and etching time were changed to study their effect to form highly ordered anodic porous alumina membranes. Forming mechanisms of highly ordered hexagon porous anodic aluminum oxide membranes, which contain a self-organize model, are discussed. According to the forming mechanisms, the factors that influence the order of nanoporous and the way that can improve it are analyzed. Formation techniques of highly ordered hexagon porous anodic aluminum oxide membranes are also included. Co nanowires CuCo alloynanowires and Cu/Co multilayered nanowires were assembled in the nanoholes of AAO template and the effect of experimental parameters such as the pH of bath and anodizing voltage were searched. The morphology of nanowires in pores of AAO was characterized by scan electron microscopy (SEM). The mechanism of alternative current electrodeposition into pores of aluminum anodic oxide template was put forward. The hysteresis loop of the nanowires showed magnetic anisotropy.