title: Controlled interconversion of nanoarray of ta dimples and high aspect ratio ta oxide nanotubes.
abstract: We report the controlled formation of either high-aspect-ratio Ta(2)O(5) nanotubes or an organized nanoarray of Ta dimples by Ta anodization in a single H(2)SO(4) + HF solution. Dimpled Ta is the stable surface morphology in the first few seconds, followed by the growth of dense and fully vertically aligned Ta(2)O(5) nanotubes (up to 2.5 microm long). After 2 min, the dimpled surface morphology reappears, related to the build-up of a resistive Ta fluoride surface layer.
authors.affiliation: Department of Chemistry, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Hany A
authors.initials: HA
authors.lastname: El-Sayed
authors.forename: Viola I
authors.initials: VI
authors.lastname: Birss