• Olga N. Kanygina Dr. Sci. (Phys.-Math.), Full Professor, Professor of the Department of General Physics, Orenburg State University, Orenburg, Russia; tel.: +7 (3532) 372439, e-mail:
  • Marina M. Filyak Cand. Sci. (Eng.), Associate Professor, Associate Professor of the Department of Industrial Electronics and Informing and Measuring Techniques, Orenburg State University, Orenburg, Russia; tel.: +7(3532) 372874, e-mail:
  • Maxim V. Ovechkin Cand. Sci. (Eng.), Associate Professor of the Department of Production Automation Systems, Orenburg State University, Orenburg, Russia; tel.: +7(3532) 752858, e-mail:
  • Lyudmila N. Guslovskaya Leading Engineer of Department of Chemistry, Orenburg State University, Orenburg, Russia; tel.: 7(3532)372485, e-mail:
Keywords: anodic alumina, alkaline electrolyte, X-ray phase analysis, colorimetry, fractal analysis.


Porous anodic aluminium oxide must be widely used in new types of micro- and nanoelectronics devices, including those operating at elevated temperatures. Therefore, it is of great importance to study the behaviour of anodic alumina films upon heating.

This paper studies phase and morphological changes in the films of anodic aluminium oxide from sodium hydroxide solutions which occur under thermal treatment. The study uses a set of physical and mathematical methods, including colorimetric, x-ray phase and fractal analyses.

Colorimetric analysis showed that after annealing, the values of reflection coefficients reduced from 65 to 57 %, which may be due to structural changes.

The samples of initial and annealed anodic aluminium oxide films were studied by X-ray phase analysis. It has been established that annealing anodized samples at a temperature of 500 ° C for 40 minutes leads to a number of changes in the hydrated alumina forms. Low-temperature modification of aluminium oxide γ - Al2О3 is formed by thermal decomposition of "hydroxide precursors". The study proposes an explanation of the thermally induced phase transformations of porous alumina which is based on the statement about different crystallization rate of Al2O3 enriched with electrolyte anions and anion-free oxide.

The interrelation between changes in micro- and macrostructures was determined by comparative fractal analysis of images of anodized samples before and after annealing. The calculation showed that the fractal dimension of the surface increased from 2.7621–2.8724 (initial samples) to 2.8193–2.8824 (after annealing). The process of annealing involves the dehydration of aluminium hydroxides accompanied by the destruction of primary crystallites, the formation of platelet particles, and an increase in the specific surface area.

The interrelation between micro- and macrostructures is of great importance for understanding the mechanisms of the formation and interdependent transitions of aluminium hydroxides and aluminium oxides. The detailed study of these mechanisms will make it possible to obtain aluminium oxides with set properties.


Download data is not yet available.


1. O'Sullivan J. P., Wood G. C. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1970, vol. 317, no. 1531, pp. 511–543. DOI: 10.1098/rspa.1970.0129
2. Lee W., Ji R., Gosele U., Nielsch K. Nature Materials, 2006, vol. 5, iss. 9, pp. 741–747. DOI: 10.1038/nmat1717
3. Roslyakov I. V., Napolsky K. S., Evdokimov P. V., Napolsky F. S., Dunayev A. V., Yeliseyev A. A., Lukashin A. V., Tretyakov Yu. D. Nanosystems: Physics, Chemistry, Mathematics, 2013, 4 (1), pp. 120–129 Available at: (in Russ.)
4. Yakovleva N. M, Yakovlev A. N., Chupakhina E. A., Khanin E. Ya. Condensed Matter and Interphases, 2006, vol. 8, no. 1, pp. 69–74. Available at: (in Russ.)
5. Vikharev A. V., Vikharev A. A. Polzunovsky Vestnic, 2010, no. 3, pp. 204–208 Available at: (in Russ.)
6. Chernyshev V. V., Kukuyev V. I., Korablin L. N. Condensed Matter and Interphases, 2005, vol. 7, no. 2, pp 200–203 Available at: (in Russ.)
7. Kanygina O. N., Filyak M. M., Ovechkin M. V. Physics and Chemistry of Materials Treatment, 2016, no. 4, pp. 52–56. (in Russ.)
8. Mark D. Fairchild. Color Appearance Model, the 2nd Edition. USA: Rochester Institute of Technology, 2006, 437 p.
9. Maslennikova G. N., Platov Yu. T., Haliullova R.A. Glass and Ceramics, 1999, no. 9, pp. 13–16. (in Russ.)
10. Software modulus FracLac 2.5 [Electronic source]: Access mode: (accessed date: 10/04/2018).
11. Mirkin L. I. Reference Book on the X-ray Diffraction Analysis of Polycrystals. Moscow State Publishing House of Physical and Mathematical Literature, 1961, 863 p. (in Russ.)
12. Chukin G. D. The Structure of Alumina and Hydrodesulfurization Catalysts. Mechanisms of Reactions. Moscow, Paladin Publ, LLC Printa, 2010, 288 p. (in Russ.)
13. Almyasheva O. V., Korytkova E. N., Maslov A. V., Husarov V. V. Inorganic Materials, 2005, vol. 41, no. 5, pp. 540–547. (in Russ.)
14. Filyak M. M., Kanygina O. N. Materials Science, 2013, no. 2, pp. 21–24. (in Russ.)
How to Cite
Kanygina, O. N., Filyak, M. M., Ovechkin, M. V., & Guslovskaya, L. N. (2018). THERMO-INDUCED PHASE-MORPHOLOGICAL TRANSFORMATIONS IN THE FILMS OF POROUS ANODIC ALUMINA FROM SODIUM HYDROXIDE SOLUTIONS. Kondensirovannye Sredy I Mezhfaznye Granitsy = Condensed Matter and Interphases, 20(3), 394-400.