Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-17T22:18:16.343Z Has data issue: false hasContentIssue false
  • English
  • Français

Material characteristics and capacitive properties of aluminum anodic oxides formed in various electrolytes

Published online by Cambridge University Press:  01 November 2004

Jeng-Kuei Chang ,
Chi-Min Liao ,
Chih-Hsiung Chen  and
Wen-Ta Tsai
Jeng-Kuei Chang
Affiliation:
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan
Chi-Min Liao
Affiliation:
New Materials Research and Development Department, China Steel Corporation, Kaoshiung 812, Taiwan
Chih-Hsiung Chen
Affiliation:
New Materials Research and Development Department, China Steel Corporation, Kaoshiung 812, Taiwan
Wen-Ta Tsai*
Affiliation:
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The microstructure and composition of aluminum oxide films, formed by a two-step anodization process in various electrolytes at 100 V then subject to an intermediate heat treatment (500 °C, 2 min), were investigated. The anodization electrolytes used included ammonium adipate electrolyte, phosphoric acid electrolyte, ammonium dihydrogen phosphate electrolyte, and their mixtures. The cross-section morphologies, crystal structure, and chemical composition of aluminum anodic oxides were examined by transmission electron microscopy. X-ray photoelectron spectroscopy was carried out to study the surface chemical state of the anodic films. The corresponding capacitances and retention voltages of these oxide films were also explored. The results indicated that amorphous-to-crystalline transformation of the oxide, primarily in films formed in ammonium adipate electrolyte, was induced by the heat treatment. Electron diffraction analyses further revealed the oxide films consisted of two distinct zones, which included an inner amorphous layer and an outer layer containing crystalline γ′-Al2O3. This study found that the phosphorous species in either the primary or the re-anodization electrolytes had a potential to cause changes of Al and O distributions within the oxides. The oxide film primarily anodized in ammonium adipate and re-anodized in phosphoric acid had the highest capacitance due to its high degree of crystallinity and thinness compared to oxides formed in other electrolytes. The presence of phosphorus, from the primary anodization electrolytes, in the oxides could inhibit the formation of crystalline γ′-Al2O3 and, consequently, decrease the capacitances of the anodic films. At the same time, the retention voltage and hydration resistance of these oxide films were improved.

Keywords

Energetic materialMicrostructureThin film
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 11 , November 2004 , pp. 3364 - 3373
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Chiu, R.L., Chang, P.H. and Tung, C.H.: Al2O3 films formed by anodic oxidation of Al-1 weight percent Si-0.5 weight percent Cu films. J. Electrochem. Soc. 142, 525 (1995).CrossRefGoogle Scholar
2Shimizu, K., Brown, G.M., Habazaki, H., Kobayashi, K., Skeldon, P., Thompson, G.E. and Wood, G.C.: Impurity distributions in barrier anodic films on aluminium: A GDOES depth profiling study. Electrochim. Acta 44, 2297 (1999).Google Scholar
3Franklin, R.W.: In Proceeding of Conference on Anodizing (Aluminum Development Association, London, 1962), p. 96.Google Scholar
4Jackson, N.F. and Campbell, D.S.: Thin films in electrolytic capacitors. Thin Solid Films 36, 331 (1976).CrossRefGoogle Scholar
5Delong, A. and Kolarik, V.: A 1:1 electron stepper. J. Vac. Sci. Technol. B 7, 1422 (1989).CrossRefGoogle Scholar
6Troyan, P.E., Lubsanov, R.B., Vorobyev, G.A., Ghyngazov, S.A., Lakstroem, I.V. and Kramor, S.S.: Flat display based on the metal– insulator–metal emitter array. J. Vac. Sci. Technol. B 11, 514 (1993).Google Scholar
7Kusunoki, T., Suzuki, M., Sakai, S., Yamaguchi, J. and Aida, T.: Fluctuation-free electron emission from non-formed metal-insulator-metal (MIM) cathodes fabricated by low current anodic oxidation. Jpn. J. Appl. Phys. 32, L1695 (1993).Google Scholar
8Shimizu, K., Kobayashi, K., Thompson, G.E. and Wood, G.C.: Electron-beam-induced crystallization of anodic barrier films on aluminium: Influence of incorporated anions. J. Appl. Electrochem. 15, 781 (1985).CrossRefGoogle Scholar
9Bernard, J.J. Randall Jr.and W.J.: A radiotracer study of the anodization of aluminum in aqueous phosphate solutions. Electrochim. Acta 20, 653 (1975).Google Scholar
10Gomez-Aleixandre, C., Montero, I. and Albella, J.: On the duplex layer nature of anodic Al2O3 films. J. Appl. Electrochem. 16, 964 (1986).Google Scholar
11Skeldon, P., Shimizu, K., Thompson, G.E. and Wood, G.C.: Fundamental studies elucidating anodic barrier-type film growth on aluminium. Thin Solid Films 123, 127 (1985).CrossRefGoogle Scholar
12Shimizu, K., Brown, G.M., Habazaki, H., Kobayashi, K., Skeldon, P., Thompson, G.E. and Wood, G.C.: Glow discharge optical emission spectrometry (GDOES) depth profiling analysis of anodic alumina films – a depth resolution study. Surf. Interface Anal. 27, 24 (1999).Google Scholar
13Crevecoeur, C. and de Wit, H.J.: The growth of anodic aluminum oxide layers after a heat-treatment. J. Electrochem. Soc. 121, 1465 (1974).CrossRefGoogle Scholar
14Kudo, T.: Cross-sections of hydrous and composite aluminum oxide films. Electrochim. Acta 23, 341 (1978).Google Scholar
15Alwitt, R.S.: The anodic oxidation of aluminum in the presence of a hydrated oxide. J. Electrochem. Soc. 114, 843 (1967).CrossRefGoogle Scholar
16Alwitt, R.S. and Dyer, C.K.: Electrical instability of composite aluminum oxide films. Electrochim. Acta 23, 355 (1978).CrossRefGoogle Scholar
17Stirland, D.J. and Bicknell, R.W.: Studies of the structure of anodic oxide films on aluminum, I. J. Electrochem. Soc. 106, 481 (1959).Google Scholar
18Crevecoeur, C. and de Wit, H.J.: in The Electrochemical Society Meeting Extended Abstracts (ECS Proc.78-1 Seattle, Washington, 1978), p. 413.Google Scholar
19Alwitt, R.S. and Takei, H. in Passivity of Metals and Semiconductors, edited by Froment, M. (Elsevier Science Publishers, Amsterdam, 1983), p. 741.CrossRefGoogle Scholar
20Choo, Y.H. and Devereux, O.F.: Barrier-type aluminum oxide films formed under prolonged anodizing – I. Influence of anodizing parameters on film morphology. J. Electrochem. Soc. 122, 1645 (1975).CrossRefGoogle Scholar
21Libsch, T.A. and Devereux, O.F.: Barrier-type aluminum oxide films formed under prolonged anodizing – II. Dielectric characteristics. J. Electrochem. Soc. 122, 1654 (1975).Google Scholar
22Anderson, P.G. and Devereux, O.F.: Steady-state anodic leakage current in barrier-type aluminum oxide films. J. Electrochem. Soc. 122, 267 (1975).Google Scholar
23Bernard, W.J. and Florio, S.M.: Anodic oxide growth on aluminum in the presence of a thin thermal oxide layer. J. Electrochem. Soc. 132, 2319 (1985).Google Scholar
24Chen, C.T. and Hutchins, G.A.: Crystalline anodic oxide growth on aluminum foil in an aqueous ammonium dihydrogen phosphate anodization electrolyte. J. Electrochem. Soc. 132, 1567 (1985).Google Scholar
25Chang, J.K., Liao, C.M., Chen, C.H. and Tsai, W.T.: Microstructure and electrochemical characteristics of aluminum anodized film formed in ammonium adipate solution. J. Electrochem. Soc. 150, B266 (2003).CrossRefGoogle Scholar
26Chang, J.K., Lin, C.M., Liao, C.M., Chen, C.H. and Tsai, W.T.: Effect of heat-treatment on characteristics of anodized aluminum oxide formed in ammonium adipate solution. J. Electrochem. Soc. 151, B188 (2004).CrossRefGoogle Scholar
27Katoh, M.: The characteristic and the evaluation of the barrier type anodic oxide film. J. Met. Finish. Soc. Jpn. 39, 420 (1988).Google Scholar
28Furneaux, R.C., Thompson, G.E. and Wood, G.C.: The application of ultramicrotomy to the electronoptical examination of surface films on aluminium. Corros. Sci. 18, 853 (1978).Google Scholar
29Shimizu, K., Brown, G.M., Kobayashi, K., Skeldon, P., Thompson, G.E. and Wood, G.C.: Ultramicrotomy—a route towards the enhanced understanding of the corrosion and filming behaviour of aluminium and its alloys. Corros. Sci. 40, 1049 (1998).Google Scholar
30Konno, H., Kobayashi, S., Takahashi, H. and Nagayama, M.: The hydration of barrier oxide films on aluminium and its inhibition by chromate and phosphate ions. Corros. Sci. 22, 913 (1982).CrossRefGoogle Scholar
31Verwey, E.J.W.: Incomplete atomic arrangement in crystals. J. Chem. Phys. 3, 592 (1935).CrossRefGoogle Scholar
32Kobayashi, K., Shimizu, K. and Teranishi, D.: Influence of electrolyte on the development of γ′-alumina in the barrier oxide layers formed on aluminum covered with a thin layer of thermal oxide. Jpn. J. Inst. Light Met. 36, 81 (1986).Google Scholar
33Kobayashi, K.: The structure of barrier anodic film on aluminum. J. Met. Finish. Soc. Jpn. 140, 1328 (1989).CrossRefGoogle Scholar