Hydrogen Distribution in Anodic Alumina Films

• Published in: Hyōmen gijutsu Vol. 49; no. 2; pp. 205 - 208
• Main Authors: MORISAKI, Shigeyoshi, MAENO, Tomokazu, YAMAMURO, Masaaki
• Format: Journal Article
• Language: English
• Published: Tokyo The Surface Finishing Society of Japan 01.02.1998; Japan Science and Technology Agency
• Subjects: Anodic Alumina Films; Hydrogen Content; Prompt Gamma-ray Analysis
• ISSN: 0915-1869; 1884-3409
• DOI: 10.4139/sfj.49.205

Electrolyte anions and water are incorporated in anodic alumina films during aluminum anodization. Component distribution is related to their physical and chemical properties and is related to the mechanism for forming anodic alumina films. Hydrogen in anodic alumina films separated from Al substrates was determined by a neutron-induced prompt gamma-ray analysis (PGA) system installed at an atomic reactor. Trace hydrogen was determined by liquid scintillation counting method for tritium in barrier films formed in an electrolyte containing tritium water. The hydrogen depth profile was measured after steps were etched into barrier films. Anodic alumina films consist of inner and outer parts, with electrolyte anions distributed to a depth half way from the outer electrolyte/oxide surface but not detected near the inner oxide/metal surface. Otherwise, 0.0035wt% hydrogen was distibuted throughout in the entire depth. We concluded that OH acts as a carrier, migrating to the oxide/metal surface and reacting with Al3+ near the oxide/metal interface.