Thickness dependence of stress in lead titanate thin films deposited on Pt-coated Si

Thickness dependence of the soft mode E(1TO) of tetraganol lead titanate thin film, deposited on Pt-coated Si by a chemical solution deposition, was determined with Raman scattering measurements. A downshift of the soft mode was attributed to the residual stress in the thin film, which was estimated in the range of 1.3–2.6 GPa, corresponding to film thickness of 400–50 nm. The variation of the clamped dielectric constants determined by observed mode frequencies was found to agree with the prediction of stress dependence of dielectric constants by Devonshire theory.