Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

• Published in: Thin solid films 2014-11, Vol.570, p.49-56
• Main Authors: Abd-Elnaiem, Alaa M., Mebed, A.M., El-Said, Waleed Ahmed, Abdel-Rahim, M.A.
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum oxide; Anodic aluminum oxide; Anodizing; Barrier layer; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electric potential; Exact sciences and technology; Formations; Inter-pore distance; Lithium; Materials science; Mesh structure; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics; Pore size; Porosity; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Voltage
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2014.08.046

Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50°C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. •We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance.•Applying low anodizing voltages onto aluminum film leads to form mesh structures.•The value of anodizing voltage (1–10V) has no effect on pore size or inter-pore distance.•Applying anodizing voltage less than 5V leads to mesh structured AAO.•AAO can be used as a matrix for Li-composite electrolytes.