2024-03-29T10:36:42Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/622062023-08-08T01:29:25Zhdl_2115_20045hdl_2115_139Ellipsometric Study of Anodic Oxide Films on Titanium in Hydrochloric Acid, Sulfuric Acid, and Phosphate SolutionOhtsuka, ToshiakiMasuda, MinoruSato, Norionodisationfilmstitaniuminorganic acidschlorine compoundssulphur compoundsphosphorus compoundsrefractive indexellipsometryscanning electron microscopy430The anodic oxide film on titanium has been studied by ellipsometry and SEM observation. Ex situ multiple‐angle‐of‐incidence and in situ ellipsometric measurements allow the complex refractive index to be estimated at n = 2.3- 2.9i for the titanium substrate and at n = 2.1-0.03i for the anodic oxide film at wavelength 546.1 nm. The anodic oxide film thickness increases linearly with potential in a range from −0.55 to 7.5V (RHE) at the rate of 2.8 nm V^−1 in phosphate solutions of pH 1.6–12.1, 2.5 nm V^−1 in 0.1M HCl solution, and 2.4 nm V^−1 in 0.1M H2SO4 solution. At potentials more positive than 7.5V, the film breaks down, leading to the formation of a thick oxide film probably due to an increased ionic current through the breakdown sites. The film composition is estimated to be TiO2(H20)l.4 or TiO0.6(OH)2.8 , which suggests the presence of hydroxyl bridge in its bonding structure.The Electrochemical SocietyJournal Articleapplication/pdfhttp://hdl.handle.net/2115/62206https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/62206/1/J.Electrochem.Soc.132%2c787-792%281985%29%2c%20Ellipsometric%20---titanium%20hydrochloric--sulfuruc--phosphate.pdf0013-46511945-7111J. Electrochemical Society13247877921985-04enginfo:doi/10.1149/1.2113958© The Electrochemical Society, Inc. 1985. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in J. Electrochem. Soc. 1985 volume 132, issue 4, 787-792.publisher