铝阳极氧化膜纳米孔阵列的微细结构

Microstructure of anodic aluminum oxide films

用电化学阳极氧化法制备了纳米多孔铝阳极氧化膜(AAO模板)．采用原子力显微镜(AFM) 测试AAO膜,研究了纳米孔阵列的形成机制．结果表明,在AAO膜的表面,除存在六方形的纳米孔阵列 外,在孔端还存在六个微小的隆起,相邻的隆起之间彼此相连,看上去酷似一朵盛开的梅花,花的中心就是 六方形纳米孔．二维AFM图像显示,以往用扫描电镜表征的纳米孔阵列,实际上是一幅排列整齐、并呈周 期性变化的梅花阵列图案．膜背面阻挡层的AFM二维图像表明,膜胞呈六方形,且排列高度有序．膜胞密 度为4．3×109／cm2,与孔密度基本一致．阻挡层的三维照片显示,膜胞的底部存在半球状突起,也呈现出 规整的阵列图案．

The anodic aluminum oxide film（namely AAO film）was prepared with the electrochemical anodization method. It could be found that the arrangement of the nanopores in AAO film is highly ordered. In order to investigate the formation reason of the nanopore array, the microstructure of AAO film was particularly studied by AFM in this paper. It shows that except hexagonal pore array in AAO film there are six small apophyses along the surface of pore wall like plum blossom. There exists a low dent between every two-neighborhood apophyses and the shape of the pore at the center of the blossom is hexagon. The nanopore arrays are actually a highly ordered plum blossom patterns. AFM image of barrier layer shows that cells are arranged in regular hexagonal network structure. The shape of the cell is also hexagon and the bottom of each cell has a hemi-sphere protuberance structure. Furthermore, the causes of formation of these microstructures were discussed in detail and the methods of investigating the order of pore and cell arrays are also given.