Vibrational spectroscopic studies on Ba0.8Sr0.2TiO3 thin films prepared byRF sputtering technique

Thin films of Ba0.8Sr0.2TiO3 have been deposited on p-type Si substrate by radio frequency magnetron sputtering. Polycrystalline bulk Ba0.8Sr0.2TiO3 s ample has also been studied for comparison. X-ray diffraction patterns reve al that both the bulk sample and thin films are polycrystalline without any preferential orientation and belong to paraelectric cubic phase. We have c ompared the room temperature Raman and IR spectra of powder and thin films (both annealed and as-deposited) of Ba0.8Sr0.2TiO3. The extra feature in th e Raman spectrum for the annealed film has been explained as due to the pre sence of intergrain stresses from the submicron size grains in it. (C) 2001 Elsevier Science Ltd. All rights reserved.