Lead zirconate titanate Pb(ZrxTi1-x)O-3 thin films with Zr/Ti ratio 40/60 (PZT40/60) and 60/40 (PZT60/40) were grown on Pt/Ti/SiO2/Si(1 0 0) substrates by a sol-gel process. Structure, surface morphologies and root mean square (rms) roughness of the, thin films were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). On the surface images of the thin films, many clusters are found, which are composed by Grains in size of about 0.5-1 and 0.15-0.2 mu m, respectively for the PZT40/60 and PZT60/40 thin films. The rms roughnesses of the PZT40/60 and PZT60/40 thin films are 2.1 and 6.7 nm, respectively. The refractive index n, the extinction coefficient k and thickness of PZT40/60 and PZT60/40 thin films annealed at 600 degrees C were obtained by spectroscopic ellipsometry as a function of the wavelength in rang from 270 to 1700 nm. (c) 2007 Elsevier B.V. All rights reserved.