【作者】 陈文；

【导师】 戴英；

【作者基本信息】 武汉理工大学 ， 材料物理与化学， 2008， 硕士

【摘要】 单晶磁性纳米线阵列在垂直磁记录领域具有广阔的应用前景,如何制备高质量的单晶纳米线阵列是其应用要解决的关键问题之一。本文对多孔氧化铝模板制备单晶磁性纳米线阵列进行了系统研究。采用二步阳极氧化法制备多孔氧化铝模板,分析了工艺参数如电化学抛光、温度、时间、通孔方式等对模板有序性和成品率的影响,获得了制备不同孔径高品质多孔氧化铝模板的最佳工艺条件。用自制的多孔氧化铝模板,采用直流电沉积的方法成功制备出Fe、Ni单质和Fe-Ni多段纳米线有序阵列。用XRD、SEM、HRTEM对纳米线阵列的组成、形貌、结构进行了分析,结果表明,制得的纳米线呈一维有序阵列排布,纳米线粗细均匀,其直径与所用模板的孔径相当,纳米线阵列沿[110]方向具有明显的择优取向性,且纳米线为沿[220]方向生长的单晶结构。根据二维成核原理分析了单晶纳米线形成条件,使用断键理论、表面能各向异性及能量最低原理解释了Fe、Ni纳米线阵列沿[110]方向择优取向的原因;通过对Ni纳米线的直流电化学沉积电流变化曲线进行分析,探讨了单晶纳米线阵列的生长动力学过程。用振动样品磁强计(VSM)对不同长径比(h/d)的纳米线阵列的磁性能进行了研究,结果表明,单晶磁性纳米线阵列具有明显的磁各向异性。更多还原

【Abstract】 It is of importance to improve the growth quality of the single-crystal magnetic nanowire arrays as it has broad applications as perpendicular magnetic recording media. The synthesis and characterization of magnetic nanowire arrays have been investigated in this thesis.Porous anodic aluminium oxide(AAO) templates have been prepared by a two-step anodization process. The effect of processing parameters such as electropolishing, temperature, time, method to remove barrier layer on the order and yield of AAO templates has been analyzed. The suitable processing conditions have been obtained to prepare high quality AAO templates.Highly ordered uniform Fe, Ni and Fe-Ni multi-layer nanowire arrays have been successfully fabricated in self-made AAO templates by DC electrodeposition method. The composition, morphology, structure of nanowire arrays have been characterized by the X-ray diffraction(XRD), scanning electron microscope(SEM) and high-resolution transmission electron microscope(HRTEM). The diameters of nanowires correspond to the pore diameter of the AAO templates and the nanowires are uniform in diameter. The nanowires arrays fabricated by AAO template have obviously preferred orientation along the [110] direction. Ni nanowire is single crystal structure and has growth orientation along [220].Growth condition of single-crystal nanowire has been analyzed by two-dimensional nucleation mechanism. The [110] preferred growth orientation of Fe, Ni nanowire arrays is explained by applying the broken-bond model in combination with surface-energy anisotropy and energy minimization. With analyzing the deposition current-time curve, the growth process of nanowire arrays in the AAO template has been confirmed.The magnetic properties of different aspect ratio(h/d) nanowire arrays have been investigated by vibration sample magnetometer (VSM). The magnetic properties of nanawire arrays with different diameters indicate that the nanowire arrays have obviously perpendicular anisotropy.更多还原