Development of a Controlled in Situ Process for the Formation of Porous Anodic Alumina and Al Nanomesh From Thin Aluminum Films

摘要

The researches on the formation of porous anodic alumina (PAA) films for use of their nanoscale properties can be divided into two main areas: growing oxide on a bulk aluminum and foils and on films deposited onto the substrate. The development of technological processes of PAA creation on bulk aluminum usually presumes the improvement of methods of ordered structures creation with implementation of a two-stage process of anodizing. This is where significant success has already been achieved [1]. However, the method of growing of ordered PAA on deposited thin aluminum films is yet to be discovered. Only the processes of nanopore ordering for PAA on thin Al films by pre-texturing by special stamps can be considered as those that secured proved results [2]. The structural difference in PAA films, grown on the bulk aluminum (plates or folds) and on the deposited films of aluminum, is usually attributed to the fact that on contrary to the annealed and subjected to the electrochemical polishing surface of bulk aluminum, the surface of the deposited film has high surface roughness, and films themselves may be disordered small-grain structure with a considerable difference in grain sizes and a large number of randomly distributed inter-grain boundaries. Aluminum films produced under various conditions also differ from each other--according to structural parameters, density of grains packing, and average values of surface roughness [3-5].