Light scattering from pulsed laser deposited BaBi4Ti4O15 thin films

Light scattering investigations are carried out on BaBi4Ti4O15 (BBiT) which is a member of the Bi-layer structure ferroelectric oxide with n = 4. The BBiT thin films, thickness similar to 300 nm, were grown on epitaxial conducting LaNiO3 electrodes on epitaxial buffer layers on (100) silicon by pulsed laser deposition. Micro-Raman measurements performed on these films reveal a sharp low-frequency mode at 51 cm(-1) along with broad high-frequency modes corresponding to other lattice vibrations including TiO6 octahedra. No temperature dependence of the low frequency mode is seen while a weak dependence of the broad high frequency vibrations are observed in the mixed oriented regions. Raman polarization carried out at room temperature indicates that the prominent modes have A(1g) and E-g symmetries in the BaBi4Ti4O15 thin films.