铝的多孔阳极氧化自组织过程结晶度依赖特性

电子束蒸发在硅衬底上的多晶铝膜多孔型阳极氧化得到的多孔列阵排布与体材料单晶铝氧化结果比较,有序度存在很大差异,导致这种差异的原因,除了氧化时间、应用电压、电解液等电化学参数外,新引入的结晶度将作为一重要因数影响自组织过程.结晶度的影响主要反映在晶粒间界区域相比于晶粒内部存在的铝原子浓度和阳极氧化反应速度涨落,这种涨落将通过干扰孔底电场的分布,对自组织过程产生微扰,由于微扰具有实时和随机性质,将使铝膜阳极氧化不再象体材铝那样,可以通过单一延长时间来最终改善孔排布的有序度.

Crystallinity Dependence of Self-organized Process During Porous Anodization of Aluminum

Porous-type anodization is carried out on thin aluminum film deposited on silicon substrate by electron beam evaporation technique. TEM examination of the obtained alumina film shows a much more less ordered pore arrangement compared with those produced from bulk aluminum under long anodization period condition. This discrepancy in pore ordering degree can be caused by many factors such as anodization period, applied electrolyte and voltage.Furthermore, a newly introduced crystallinity should also be carefully taken into account. Due to the polycrystalline structure of the thin A1 film rather different from that nearly single crystalline of bulk Al, the inteffacial region of its Al grains, which induces some extent of fluctuation in atomic density and relative anodizing rate along the direction of the pore development in comparison with groins themselves, will give an effect to the self-organized process during anodization by disturbing the electric field distribution at the pore bottom.