Morphology and fractal dimension of TiO2 thin films

Srdjan P Petrović


The influence of annealing temperature on the morphology and surface fractal dimension of titanium dioxide (TiO2) films prepared via the spray deposition process was investigated. Thin films with various morphologies were obtained at different temperatures and characterized by X-ray diffraction and atomic force microscopy (AFM). It was found that the crystalline structure of TiO2 films depends strongly on annealing temperature. At higher temperatures, the partial phase transformation of anatase-to-rutile was observed. The morphology and surface fractal dimensions were evaluated by image analysis methods based on AFM micrographs. The results indicate that the value of surface roughness (the standard deviation of the height values within the given area of AFM image) of TiO2 films increases with increasing annealing temperature. Fractal analysis revealed that the value of the fractal dimension of the samples decreases slowly from 2.23 to 2.15 following the annealing process.




fractal characteristic; surface morphology; TiO2 thin films; atomic force microscopy;

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A. Fernández, G. Lassaletta, V. M. Jiménez, A. Justo, A. R. González-Elipe, J.-M. Herrmann, H. Tahiri, Y. Ait-Ichou, Preparation and characterization of TiO2 photocatalysts supported on various rigid supports (glass, quartz and stainlesssteel). Comparative studies of photocatalytic activity in water purification, Appl. Catal. B-Environ., 7, 49–63 (1995).

W. Zhang, K. Wang, Y. Yu, H. He, TiO2/HZSM- 5 nano-composite photocatalyst: HCl treatment of NaZSM-5 promotes photocatalytic degradation of methyl orange, Chem. Eng. J, 163, 62–67 (2010).

N. Rao Neti, G. Rani Parmar, S. Bakardjieva, J. Subrt, Thick film titania on glass supports for vapor phase photocatalytic degradation of toluene, acetone, and ethanol, Chem. Eng. J, 163, 219–229 (2010).

G. Balasubramanian, D. D. Dionysiou, M. T. Suidan, I. Baudin, J.-M. Laine, Evaluating the activities of immobilized TiO2 powder films for the photocatalytic degradation organic contaminants in water, Appl.Catal. B-Environ., 47, 73–84 (2004).

H. D. Jang, S. K. Kim, S.-J. Kim, Effect of particle size and phase composition of titanium dioxide nanoparticles on the photocatalytic properties, J. Nanopart. Res., 3, 141–147 (2001).

Y. Chen, D. Dionysiou, A comparative study on physicochemical properties and photocatalytic behavior of macroporous TiO2- P25 composite films and macroporous TiO2 films coated on stainless steel substrate, Appl. Catal. A-Gen., 317, 129–137 (2007).

A. I. Kontos, A. G. Kontos, D. S. Tsoukleris, M. C Bernard, N. Spyrellis, P. Falaras, Nanostructured TiO2 films for DSSCS prepared by combining doctor-blade and sol-gel techniques, J. Mater. Process. Tech., 196, 243–348 (2008).

C. Trapalis, N. Todorova, M. Anastasescu, C. Anastasescu, M. Stoica, M. Gartner, M. Zaharescu, T. Stoica, Atomic force microscopy study of TiO2 sol-gel films thermally treated under NH3 atmosphere, Thin Solid Films, 517, 6243–6247 (2009).

J. Dostanić, B. Grbić, N. Radić, P. Stefanov, Z. Šaponjić, J. Buha, D. Mijin, Photodegradation of an azo pyridone dye using TiO2 films prepared by the spray pyrolysis method, Chem. Ing. J., 180, (2012) 57–65.

A. De Giacomo, V. A. Shakhatov, G. S. Senesi, S. Orlando, Spectroscopic investigation of the technique of plasma assisted pulsed laser deposition of titanium dioxide, Spectrochim. Acta B, 56, 1459– 1472 (2001).

W. Guo, J. F. Porter, Ch. M. Chan, Ch. K. Chan, Characterization of ultrafine titanium dioxide powders produced by vapor phase hydrolysis of titanium tetraisopropoxide, J. Aerosol Sci., 28, S485–S486 (1997).

M. A. Khadar, N. A. M. Shanid, Nanoscale finestructure evaluation of RF magnetron sputtered anatase films using HRTEM, AFM, micro-Raman spectroscopy and fractal analysis, Surf. Coat. Tech., 204, 1366–1374 (2010).

A. P. Xagas, E. Androulaki, A. Hiskia, P. Falaras, Preparation, fractal surface morphology and photocatalytic properties of TiO2 films, Thin Solid Films, 357, 173–178 (1999).

W. Kwaśny, L. A. Dobrzański, Structure, physical properties and fractal character of surface topography of the Ti + TiC coatings on sintered high steel, J. Mater. Process. Tech., 164-165, 1519–1523 (2005).

A. Mannelquist, N. Almqvist, S. Fredrikson, Influence of tip geometry on fractal analysis of atomic force microscopy images, Appl. Phys. A- Mater., 66, S891–S895 (1998).

F. Feng, K. Shi, S.-Z.Xiao, Y.-Y. Zhang, Z.-J. Zhao. Z. Wang, J.-J. Wei, Z. Han, Fractal analysis and atomic force microscopy measurements of surface roughness for Hastelloy C276 substrates and amorphous alumina buffer layers in coated conductors, Appl. Surface Sci., 258, 3502–3508 (2012).

E. S. Gadelmawla, M. M. Koura, T. M. A. Maksoud, I.M. Elewa, H.H. Soliman, Roughness parameters, J. Mater. Process. Tech., 123, 133–145 (2002).

J. B. Florindo, M. S. Sikora, E. C. Perira, O. M. Bruno, Characterization of nanostructured material images using fractal descriptors, Physica A, 392, 1694–1701 (2013).

S. Stojadinović, N. Radić, R. Vasilić, M. Petković, P. Stefanov, Lj. Zeković, B. Grbic, Photocatalytic properties of TiO2/WO3 coatings formed by plasma electrolytic oxidation of titanium in 12-tungstosilicic acid, Appl. Catal. B Environ., 126, 334–341 (2012).

C. Tealdi, E. Quartarone, P. Galinetto, M. S. Grandi, P. Mustareli, Flexibile deposition of TiO2 electrodes for photocatalytic application: Modulation of the crystal phase as a function of the layer thickness, J. Solid State Chem., 199, 1–6 (2013).

T. Novaković, N. Radić, B. Grbić, T. Marinova, P. Stefanov, D. Stojčev, Oxidation of n-hexane over Pt and Cu-Co oxide catalysts supported on a thinfilm zirconia/stainless steel carrier, Catal. Commun., 9, 1111–1118 (2008).

R. W. G. Wyckoff, Crystal Structures 1. Second edition, Interscience Publishers, New York, 1963, pp. 239–444.

S. Bakardjieva, J. Šubrt, V. Štengla, M. J. Dianez, M. J. Sayagues, Photoactivity of anatase-rutile TiO2 nanocrystalline mixtures obtained by heat treatment of homogeneously precipitated anatase, Appl. Catal. B Environ., 58, 193–202 (2005).

C. Wen-Shiung, Y. Shang-Yuan, H. Chih Ming, Two algorithms to estimate fractal dimension of grey-level images, Optical Engineering, 42(8), 2452–2464 (2003).

K. T. Lam, L. W. Ji, Fractal analysis of InGaN selfassemble quantum dots grown by MOCVD, Microelectron. J., 38, 905–909 (2007).



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