Ferro- and piezoelectric properties of intergrowth Bi4Ti3O12–BaBi4Ti4O15 thin film

Bi4Ti3O12–BaBi4Ti4O15 (BT–BBTi) thin film was deposited on Pt (111)/Ti/SiO2/Si substrate using the sol–gel method. Both BT–BBTi film and the powder sample derived from the same coating solution were demonstrated to possess an intergrowth structure according to X-ray diffraction patterns. The remanent polarization for BT–BBTi thin film was as large as 20 μC/cm2, which is about 30% higher than that of BBTi (∼15 μC/cm2) along a axis. The predicted Pr value for uniformly crystallized a-axis-oriented BT–BBTi film should be larger than 40 μC/cm2 according to the piezoelectric measurements using an atomic force microscope in the piezoresponse mode. The BT–BBTi film exhibited good fatigue resistance after 109 switching cycles.