Structural and electrical characterization of Bi2VO5.5 / Bi4Ti3O12 bilayer thin films deposited by pulsed laser ablation technique

摘要

The pulsed laser ablation technique has been employed to fabricate bilayer thin films con-sisting of layered structure ferroelectric bismuth vanadate (Bi2VO5.5) and bismuth titanate (Bi4Ti3O12) on platinized silicon substrate. The phase formation of these films was confirmed by X-ray diffraction (XRD) studies and the crystallites in these bilayers were randomly oriented as indicated by diffraction pattern consisting of the peaks corresponding to both the materials. The homogeneous distribution of grains (~300 nm) in these films was confirmed by atomic force microscopy. The cross-sectional scanning electron microscopy indicated the thickness of these films to be around 350 nm. The film exhi-bited P-E hysteresis loops with Pr ~ 11 ?C/cm2 and Ec ~ 115 kV/cm at room temperature. The dielectric constant of the bilayer was ~ 225 at 100 kHz which was higher than that of homogeneous Bi2VO5.5 film.