AAO template;; nanowires;; coercivity;; binary alloy;; DC deposition

Title: ferromagnetic / non-ferromagnetic Ni-Zn, Co-Zn and oxides Preparation and properties of nanowires
Author: Liu Lihu
Degree-granting units: Hebei Normal University
Keywords: AAO template;; nanowires;; coercivity;; binary alloy;; DC deposition
Abstract:
Based on Anodic Aluminum Oxide (AAO), using direct current deposition were successfully prepared a series of ferromagnetic / non-ferromagnetic Ni-Zn, Co-Zn Series Composite nanowires, followed by post-annealing of the alloy nanowires at different Rare earth magnets temperatures, different annealed under the conditions of the atmosphere, get alloy oxide nanowires, and their products were related materials research.
This body can be divided into three parts:
1 First, we used secondary oxidation in the laboratory were prepared by AAO template with different specifications. Given the existence of the electrolyte during the preparation of many factors, such as: composition, concentration, pH, and oxidation of the impact of voltage on the template, this paper, using a variety of different electrolytes, and through the rational regulation of the above parameters, a more satisfactory preparation the AAO template. And scanning electron microscopy (SEM) and atomic force microscope (AFM) for surface and internal structure of the AAO templates were characterized. The results show, respectively, in sulfuric acid and oxalic acid electrolyte in the pores is more prepared AAO template rules, and in the preparation of phosphoric acid in the pores of the template is easy to fork; the other hand, under the same conditions, phosphoric acid template http://www.chinamagnets.biz/ prepared the largest aperture, oxalic acid solution, followed by preparation of the template aperture, while the sulfuric acid solution prepared by the template pore size minimum.
2 The second part, based on the front of the AAO template obtained using the self-cell, using direct current deposition, respectively, were prepared at different voltages NixZn1-x, CoxZn1-x series of binary metallic compound nanowires, respectively X-ray diffraction (XRD), electron spectroscopy (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and other composite nanowires of binary metal structure, composition and morphology were characterized. The results show that DC chemical deposition method, binary metal compound can Nanowires; use of the metal between elements Dian Huaxue bit different, by changing the deposition voltage of the alloy elements of the nanowires than Zufen adjust thus affecting the microstructure of alloy nanowire composition.
The successful synthesis of the alloy nanowires, the use of multi-functional physical performance test systems (PPMS) for the magnetic properties of nanowire arrays were studied. By NixZn1-x, CoxZn1-x binary metallic composite nanowire arrays of magnetic measurements show that low-voltage alloy nanowire deposition shown by the magnetic anisotropy is weak, with the deposition voltage increases, the nanowires Africa ferromagnetic metallic zinc will gradually increase, and nanowire system showed strong magnetic anisotropy. For NixZn1-x alloy nanowires, we believe that this change is due to the deposition process in the alloy of the ferromagnetic metal into Africa, undermining the integrity of the original magnetic nanowires, the magnetostatic coupling and shape anisotropy together the result; while the latter is due to Co2 + ions in the nanowires caused by the change of the content of magnetic anisotropy and shape anisotropy of nanowires result of the role.
3 by the binary metallic composite nanowires at different temperatures, different atmosphere post-annealing conditions, and successfully prepared Co-doped ZnO ferromagnetic metal nanowires, and CoxZn1-xO morphology and structure were characterization, the use of PPMS system to its magnetic properties were measured, and found that all CoxZn1-xO nanowire samples showed room temperature ferromagnetic effect, we believe that this is because the annealing process in the nanowires caused by the redistribution of Co atoms, leading to Co2 + coupling between ions caused by the change.
Degree Year: 2010