Thin film growth of SrBiTiO system by PLD method and optical characterization

SrBi4Ti4O15, Sr2Bi4Ti5O18 and Sr3Bi4Ti6O21 thin films were grown on (100)MgO and (100)Pt/ (100)MgO substrates by the pulsed laser deposition (PLD) method. X-ray diffraction (XRD) revealed c-axis-oriented crystal growth of each SiBiTiO film. Reflection high-energy electron diffraction (RHEED) from the films grown on MgO showed streak patterns which indicates the epitaxial ordering of fabricated thin films. Fundamental optical absorption of SrBi4Ti4O15, Sr2Bi4Ti5O18 and Sr3Bi4Ti6O21 films started at 3.4. 3.5 and 3.7 eV, respectively. Moreover, the Fourier transform infrared (FT1R) spectra also revealed a systematic change in their longitudinal optical (LO) phonon absorption dip structure.