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1、.论文：多孔阳极氧化铝模板及磁性纳米线/管的制备与研究【中文摘要】多孔阳极氧化铝模板（anodic aluminum oxide, AAO）由于制备简单，孔径大小可控，化学性质稳定，已经获得了广泛的应用，本文采用两步阳极氧化法制备了一系列阳极氧化铝模板并采用电化学沉积的方法在模板中制备了Fe、Ni纳米线及纳米管阵列，采用X射线粉末衍射仪（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和振动样品磁强计（VSM）对样品的成分、结构、形貌和磁性进行了研究。主要工作如下：(1)分别以硫酸、草酸和磷酸为电解液制备了一系列的氧化铝模板，主要研究了氧化电压，电解液温度，二次氧化时间及扩孔时间对
2、模板形貌的影响。结果发现，以硫酸作为电解液时制备的模板孔径最小，一般小于30nm；草酸作为电解液时，要想制备有序的模板，氧化电压不易太高，一般在30-80V之间，制备的模板孔洞较小，直径在几十纳米左右；磷酸作为电解液时，制备有序模板的氧化电压较高，一般在100-200V之间，制备的模板孔洞较大，直径可达几百纳米。无论以何种酸作为电解液，在一定范围内都有如下规律：模板的孔径随氧化电压的升高而增大；降低电解液温度模板孔洞的有序度提高；延长二次氧化时间可以增加孔的深度；孔径与扩孔时间成线性关系。通过一系列的实验，掌握了制备模板特定孔径大小和膜厚的实验条件，为进一步制备一维纳米材料做好了准备。(2)采
3、用直流电沉积法在双通氧化铝模板中制备了一系列Fe纳米线阵列，并研究了模板的孔径和沉积电压与纳米线形貌和磁性的关系。结果表明，所制备的Fe纳米线为（111）和（211）的多晶结构。直径与所使用模板的孔径一致，外加磁场沿纳米线方向比垂直纳米线方向的矫顽力大，而且，随着所用模板孔径的增加，纳米线的直径增加，长径比减小，导致形状各向异性能减小，因而矫顽力和剩磁都随之降低。沉积电压对纳米线的长度和表面形貌都有重要影响，沉积电压为-1.1V时，Fe纳米线表面最光滑而且此时纳米线比较长，矫顽力出现最大值，上述结果说明纳米线的磁性不仅受长径比的影响还受其表面形貌的影响。(3)采用直流电沉积法在AAO模板中制备
4、了Ni纳米线和纳米管，结果表明，所制备的Ni纳米线表面光滑，长径比较大，外加磁场沿纳米线方向的矫顽力大于垂直方向的。制备的Ni纳米管外壁光滑，管壁较薄，粗细均匀，与外磁场垂直于纳米管相比，当磁场平行于纳米管时，矫顽力大而且此时易于达到饱和，纳米管的易磁化轴沿管的轴线方向，因为其形状各向异性占主导作用，纳米线和纳米管磁性上的差别是由于其纳米微结构不同所致。【英文摘要】Porous anodic aluminum oxide (AAO) templates have got a widerange of applications owing to their simple preparation,
5、 easy controlof nanopores and chemical stability. In this paper, a series of AAOtemplates were first prepared by using the two-step anodizationprocess, and then Fe, Ni nanowire and nanotube arrays wereelectrochemically deposited into these AAO templates. The structureand morphology of the nanomateri
6、als were analyzed by x-raydiffraction (XRD), transmission electron microscopy(TEM) andscanning electron microscopy (SEM). The magnetic measurementswere performed using vibrating sample magnetometer (VSM).Conclusions presented in this paper can be summarized as follows:(1) A series of ordered AAO tem
7、plates were obtained in sulfuricacid, oxalic acid and phosphoric acid, respectively. We studied theimpact of oxidation voltage, electrolyte temperature, oxidation timeand pore widening time on the morphology of the membranes. It isfound that diameter of the AAO templates prepared in sulfuric acid el
8、ectrolyte is less than 30 nm. When oxalic acid used as electrolyte,and the oxidation voltage is 30-80 V, we can obtain AAO templateswith diameter of several tens nanometers. When phosphoric acidused as electrolyte, and the oxidation voltage is 100-200 V, we canobtain AAO templates with diameter of s
9、everal hundred nanometers.No matter what kinds of acid used as the electrolyte we can have thefollowing rules within a certain range: the diameter of AAO templatesincreases with increasing oxidation voltage and pore widening time.By extending the secondary oxidation time we can increase thethickness
10、 of the template. Through a series of experiments, we havegot some experimental conditions for the preparation of a templatewith specific size, which can be used for the next preparation ofone-dimensional nanomaterials.(2) A series of Fe nanowire arrays were prepared byelectrochemical deposition met
11、hod in the through hole templates. Wehad studied the impact of pore diameter size and oxidation voltage onFe nanowiremorphology and magnetic properties.The results showthat the Fe nanowires are polycrystal with (111) and (211) diffractionpeaks, and the diameter of the nanowires is consistent with th
12、e porediameter of the AAO templates. The coercivity is higher when the fieldis applied parallel to the axis of the nanowires than that when the fieldis perpendicular to the axis. In addition, the nanowires aspect ratio decreases with the increase of the template diameter, which willdecrease the shap
13、e anisotropy. Therefore, the coercivity andremanence decrease accordingly. Both length and morphology of thenanowires are strongly influenced by the oxidation voltage. When theoxidation voltage is -1.1V, Fe nanowires show a very smooth surfaceand long length, and have a maximum coercivity. Consequen
14、tly, themagnetic property of nanowires is strongly inflenced not only by theaspect ratio but also by the morphology.(3) Ni nanowires and nanotubes were obtained by electrochemicaldeposition method. The results show that Ni nanowires have a verysmooth surface and large aspect ratio. The coercivity is
15、 higher whenthe field is applied parallel to the axis of the nanowires than that whenthe field is perpendicular to the axis. The Ni nanotubes have smoothouter wall, thin tube wall and uniform wall thickness. The coercivity inthe parallel direction of the nanotubes is larger when compared tothat in t
16、he perpendicular direction, and the easy magnetizationdirection is oriented along the nanotubes axis bacause the shapeanisotropy occupied a dominant position. The different magneticproperties of Ni nanotubes and nanowires may be due to thedifference of their morphology.【关键词】多孔阳极氧化铝模板 电化学沉积法 磁性纳米线 磁性纳米管【英文关键词】porous anodic aluminum oxide templates electrochemical deposition magnetic nanowires magnetic nanotubes【目录】多孔阳极氧化铝模板及磁性纳米线/管的制备与研究摘要3-5Abstract
