Abstract
High-voltage anodization is well known for producing nanostructures such as porous alumina and TiO2 nanotubes. The formation mechanisms involve an intricate balance between oxide growth and dissolution in which pore initiation and propagation is convoluted with the need for strain relief. Laser ablation with a nanosecond pulsed Nd:YAG laser (532 nm) produces texture e.g. arrays of pillars, macropores and ripples. Nanoparticles produced in the ablation plume can also be deposited on the target or a remote substrate. These substrates are anodized in solutions typically used for porous film and nanotube production (including viscous fluoride-containing electrolytes). A number of metals have been investigated, with emphasis here on Al and Ti as well as Zn. Laser pre-texturing results in the formation of structures unattainable by anodization alone. Deposited nanoparticles of Al and Zn are found to act as seeds for the growth of oxide crystallites that fuse into porous crystallite films.