Structural and ferroelectric characterization of Bi3.25La0.75Ti3O12 thin films prepared by using metalorganic deposition

Abstract

Bi3.25La0.75Ti3O12 (BLT) thin films with a polycrystalline structure were deposited onto Pt/Ti/SiO2/Si substrate by using a metalorganic decomposition method (MOD). The layered perovskite structure was investigated using annealing for I h in the temperature range from 550similar to750 degreesC. The structural properties of the BLT films were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Field emission scanning electron microscopy (FESEM) showed uniform surfaces composed of rod-like grains without cracks and pin-holes. The grain size of the BLT films increased with increasing annealing temperature. The hysteresis loops of the films were well defined at temperatures above 600 degreesC. The BLT film annealed at 650 degreesC exhibited a 2 dielectric constant of 279, a dielectric loss of 1.8 %, a remanent (2P(r)) polarization of 25.66 muC/cm(2), and a coercive field (E-c) of 84.75 kV/cm. The BLT thin films showed good fatigue endurance up to 3.5 x 10(9) bipolar cycling at 5 V and 50 kHz.