Barium strontium titanate ( Ba _0.8 Sr _0.2 TiO ₃) thin films have been prepared on Pt/Ti/SiO ₂ /Si substrates using a soft solution processing. X-ray diffraction and also micro-Raman spectroscopy showed that the Ba _0.8 Sr _0.2 TiO ₃ thin films exhibited a tetragonal structure at room temperature. The presence of Raman active modes was clearly shown at the 299 and 725 cm ^-1 peaks. The tetragonal-to-cubic phase transition in the Ba _0.8 Sr _0.2 TiO ₃ thin films is broadened, and suppressed at about 35 °C, with a maximum dielectric constant of 948 (100 kHz). Electrical measurements for the prepared Ba _0.8 Sr _0.2 TiO ₃ thin films showed a remnant polarization ( P _r) of 6.5 μC/cm ², a coercive field (E_c) of 41 kV/cm, and good insulating properties. The dispersion of the refractive index is interpreted in terms of a single electronic oscillator at 6.97 eV. The direct band gap energy (E_g) and the refractive index (n) are estimated to be 3.3 eV and n = 2.27–2.10, respectively. © 2002 American Institute of Physics.