Growth and characterization of pulsed-laser-deposited polycrystalline Bi3.33Sm0.67Ti3O12 ferroelectric thin films

Ferroelectric Bi3.33Sm0.67Ti3O12 (BSmT) thin films have been fabricated on Pt/TiOx/SiO2/Si substrates by pulsed laser deposition and their structural and ferroelectric properties have been characterized. The structure and morphology of the films were characterized using X-ray diffraction, atomic force microscopy, and scanning electron microscopy. About 520-nm-thick BSmT films grown at 700 °C exhibit excellent ferroelectric properties with a remanent polarization (2Pr) of 41.8 μC/cm2 and coercive field (Ec) of 91.0 kV/cm, at an applied electric field of 385 kV/cm. The leakage current density was 2.0 × 10− 6 A/cm2 at a dc electric field of 200 kV/cm. The films also demonstrate fatigue-free behavior up to 109 read/write switching cycles with 1 MHz bipolar pulses at an electric field of 192 kV/cm. As a result, Sm-substituted bismuth titanate films with good ferroelectric properties and excellent fatigue resistance are useful candidates for ferroelectric memory applications.