Local observation of ferroelectric Bi3.25La0.75Ti3O12 thin films by atomic force microscopy

Abstract

Ferroelectric M3.25La0.75Ti3O12 (BLT) thin films have been grown by a sol-gel method. Annealing conditions after the drying process have been explored over a wide range of temperature. Highly (001)- and (h00)-oriented BLT thin films are prepared on Pt/TiO2 coated SiO2/Si(100), depending on annealing temperature. Structural properties, surface morphology, and electrical properties are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic electron microscopy (AEM), respectively. Ferroelectric domains in the thin films are observed by using AFM, registering the electrostatic force response of the thin films in the presence of a low ac field. It is found that the as-grown domain configuration and switching behavior are strongly dependent on crystal orientation, suggesting that annealing temperature is related to domain formation and its polarization-reversal dynamics.