线径调制Ni纳米线的制备及其磁性

Fabrication and Magnetic Properties of Ni Nanowires with Modulated Diameters

实验基于非对称二次阳极氧化方法,通过在多种不同的电解液中交替阳极氧化制备了孔径大小调制的多孔氧化铝,并以此为模板,电化学沉积了线径调制的Ni纳米线。采用场发射扫描电镜对Ni纳米线进行了形貌表征,照片显示纳米线粗、细段的直径分别约为65和35 nm。X射线衍射分析结果表明Ni纳米线沿着<220>方向择优生长。采用综合物性测量系统测量了不同温度下纳米线阵列的磁滞回线。结果表明调制Ni纳米线的矫顽力随温度变化很小,其矫顽力主要取决于纳米线的形状各向异性。最后对Ni纳米线的反磁化过程进行了分析讨论。

Based on the asymmetrical two-step anodic oxidation process, the porous anodic alumina with modulated pore diameters was fabricated by alternate anodization of aluminum in several different electrolytes. Modulated anodic alumina membranes sever as the template for the electrodeposition of Ni nanowires with modulated diameters. The morphology of Ni nanowires was characterized by field emission scanning electron microscope. And the photographs show that the diameters of thick and thin segments of nanowires are about 65 nm and 35 nm, respectively. The analysis result of X-ray diffraction reveals that Ni nanowires grow in a preferred orientation of 〈 220 〉 direction. The hysteresis loops of nanowires array were measured by physical properties measurement system at different temperatures. The result indicates that the coereivity of modulated Ni nanowires changes little with the temperature, which is mainly determined by the shape anisotropy. The magnetic reversal process of the Ni nanowire was discussed.