Structural and optical properties of (Pb,Ca)TiO3 thin films prepared by a sol-gel technique

Transparent and crack-free calcium modified lead titanate thin films were p repared on platinum-coated silicon and fused quartz substrates by a set-gel technique. Lead acetate trihydrate, calcium nitrate tetrahydrate and titan ium tetra-n-butoxide were used as starting materials. Methanol and ethanola mine were used as solvent and stabilizing agent, respectively. The structur al properties of the thin films were studied by x-ray diffraction technique . Optical transmission and absorption properties of the thin films were mea sured in the wavelength range of 200-1100 nm. The thin films possess good o ptical transmissitivity. By using an approximate formula, the refractive in dex and band gap were evaluated. The optical transitions of the thin films are direct in nature. The dispersion relation of refractive index and wavel ength follows the single electron oscillation model.