Álvarez Herrero, AlbertoRamos Zapata, GonzaloMonte Muñoz de la Peña, Francisco delLevy, DavidBernabeu Martínez, Eusebio2023-06-202023-06-202004-05-011. C.J. Brinker, G.W. Scherer, Sol–Gel Science, Academic Press, New York, 1990. 2. A. Morales, A. Durán, J. Sol–gel Sci. Tech. (1997) 451. 3. G.C. Righini, S. Pelli, J. Sol–gel Sci. Tech. (1997) 991. 4. T. Belenguer, P. Cheben, E.M. Moreno, A. Núñez, M. Ulibarrena, F. Del Monte, D. Levy, Opt. Lett. 21 (1996) 1857. 5. F. del Monte, G. Ramos, T. Belenguer, D. Levy, Proc. SPIE 4802 (2002) 51. 6. S.J. Gregg, K.S.W. Sing, Adsorption, Surface Area and Porosity, Academic Press, New York, 1997. 7. G. Ramos, F. Del Monte, M. Zayat, M.L. Ferrer, D. Levy, J. Sol–Gel Sci. Tech. 26 (2003) 869. 8. A. Álvarez-Herrero, H. Guerrero, E. Bernabéu, D. Levy, Appl. Opt. 41 (2002) 6692. 9. A. Álvarez-Herrero, R.L. Heredero, E. Bernabéu, D. Levy, Appl. Opt. 40 (2001) 527.0040-609010.1016/j.tsf.2004.01.023https://hdl.handle.net/20.500.14352/51204© 2004 Elsevier B.V.High refractive index TiO_2–SiO_2 thin films were prepared by the sol–gel method and the optical properties were characterized by spectroscopic ellipsometry. The results of the optical analysis were related with the TiO_2–SiO_2 molar ratio of the porous films. It was obtained that the higher is the TiO_2 molar ratio, the higher is the refractive index and the lower is the thickness under the same deposition conditions. In fact, when the TiO_2–SiO_2 molar ratio varies from 70–30% to 100–0%, the refractive index and the thickness vary from ~1.85 to ~1.95 λ=500 nm and from ~65 nm to ~40 nm, respectively. The water adsorption in the pores of the material produces a change in the refractive index of the film. The variation of the optical properties with the environmental relative humidity was also studied. In addition, information about the size and the shape of the pores was extracted from the water adsorption isotherms measured by ellipsometry.engjournal articlehttp://dx.doi.org/10.1016/j.tsf.2004.01.023http://www.sciencedirect.comopen access535SurfaceÓptica (Física)2209.19 Óptica Física