Optical and structural properties of ZnO + Zn2TiO4 thin films prepared by the sol–gel method
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ZnO + Zn2TiO4 thin films were obtained by the sol–gel method using precursor solutions with different Ti/Zn ratios in the 0.18–2.13 range. The films were deposited on glass substrates and annealed in an open atmosphere at 550 °C. The oxide was characterized by X-ray diffraction and photoacoustic (PA) spectroscopy. The films were constituted of polycrystalline ZnO for the lowest Ti/Zn ratio (0.18), polycrystalline Zn2TiO4 for the 0.70 and 1.0 ratios, and mixes of both oxides for the intermediate ratios (0.32 and 0.50). For the highest ratios studied (1.44 and 2.13), the films were amorphous. The energy band gap (Eg) values were determined from optical absorption spectra, measured by means of the PA technique spectra. Eg varied in the 3.15 eV (ZnO) to 3.70 eV (Zn2TiO4) range.
This work was supported by Secretaría del Medio Ambiente y Recursos Naturales (SEMARNAT) and Consejo Nacional de Ciencia y Tecnología (CONACYT) under project Semarnat-2002-C01-1416/A-1. The authors wish to thank C. I. Zúñiga Romero and Ing. José Eleazar Urbina Alvarez for their technical assistance.
- 1.S.P. Walvekar, A.B. Halgeri. Proc. Indian Nat. Sci. Acad. 41, 117 (1975)Google Scholar
- 6.G. Marci, V. Augugliario, M.J. López-Muñoz, C. Martin, L. Palmesano, V. Rives, M. Schiavello, R.J.D. Tilley, A.M. Venezia, J. Phys. Chem. B 105, 23 (1997)Google Scholar
- 9.JCPDS Cards: ZnO, 38-1451. TiO2,73-1764. Zn2TiO4, 77-0014Google Scholar
- 10.J. Yang, J. H. Swisher, Mater. Charact. 37 (1996) 153–159. F.H. Dulin, D.E. Rase, J.Am.Ceramic Soc. 43, 125 (1960)Google Scholar