Figure 1.

Comparison of the relationship between the applied potential and corresponding I-t curve and HR-FESEM micrographs. (a) Comparison of the relationship between the applied potential (E) and the corresponding current (I) as a function of time (t) using DCA and HPA. (b, c, d) HR-FESEM micrographs of a typical porous alumina surface morphology using DCA and HPA on the low-purity (99%) and high-purity (99.997%) Al foils.