title: Fabrication of alumina films with laminated structures by ac anodization.
abstract: Anodization techniques by alternating current (ac) are introduced in this review. By using ac anodization, laminated alumina films are fabricated. Different types of alumina films consisting of 50-200 nm layers were obtained by varying both the ac power supply and the electrolyte. The total film thickness increased with an increase in the total charge transferred. The thickness of the individual layers increased with the ac voltage; however, the anodization time had little effect on the film thickness. The laminated alumina films resembled the nacre structure of shells, and the different morphologies exhibited by bivalves and spiral shells could be replicated by controlling the rate of increase of the applied potentials.
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Hiroyo
authors.initials: H
authors.lastname: Segawa
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Hironaga
authors.initials: H
authors.lastname: Okano
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Wada
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Inoue
keywords: Ac anodization; Anodic aluminum oxide (AAO); Biomimetics of nacre; Laminated layer; Nanowire