Effect of grain size on ferroelectric and dielectric properties of Bi3.25La0.75Ti3O12 thin films prepared by rf-magnetron sputtering

Abstract

Bi[Formula: see text]La[Formula: see text]Ti3O[Formula: see text](BLT) thin films are promising materials used in non-volatile memories. In this work, BLT films were deposited on Pt(111)/Ti/SiO2/Si substrates by rf-magnetron sputtering method followed by annealing treatments. The microstructures of BLT thin films were investigated via X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). With the increase in annealing temperature, the grain size increased significantly and the preferred crystalline orientation changed. A well-saturated hysteresis loop with a superior remnant polarization of 15.4 [Formula: see text] C/cm2 was obtained for BLT thin films annealed at 700[Formula: see text]C. The results show that the dielectric constant decreased with the increase in grain sizes.