ABSTRACT
Thin films of Bi3.25La0.75Ti3O12 (BLT) and B-site substituted BLT by Zr, i.e. Bi3.25La0.75Ti3−x Zr x O12 (BLTZx, x = 0.20, 0.50, 0.75, 1.00 and 1.50) were fabricated on Pt/TiO2/SiO2/Si substrates by RF magnetron sputtering method. Effect of Zr4+ amount on the microstructure and ferroelectric characteristics of the thin film BLTZx were investigated. X-ray diffraction shows that A-site La3+ and B-site Zr4+ co-substitution do not destroy the layered perovskite structure. Compared with the well-known BLT thin films, appropriate Zr4+ added, such as the BLTZ0.20 thin film, has larger remnant polarization (2Pr) and better fatigue resistance. However, with further increasing Zr4+-doping concentration, the remnant polarization (2Pr) tends to decrease. When x > 0.75 the remnant polarization become lower than that of BLT thin film. The remnant polarization (2Pr) of the BLTZx thin films under the 12 V were 17.8, 25.6, 22.4, 17.2, 11.6, 10.2 μC/cm2, respectively, for x = 0, 0.20, 0.50, 0.75, 1.00 and 1.50, whereas there are almost no obvious difference in the Vc values.
ACKNOWLEDGMENTS
This work is jointly supported by the Key program of National Nature Science Foundation of China (No. 90407023), Analytical and testing center of Huazhong University of Science and Technology.