The Effect of La-Doped Bi₄Ti₃O₁₂ Buffer Layer on Crystallinity and Ferroelectric Properties of PbZr_0.58Ti_0.42O₃/Bi_3.25La_0.75Ti₃O₁₂ Multilayered Thin Films

Abstract

Abstract PbZr0.58Ti0.42O3 (PZT) ferroelectric thin films with Bi3.25La0.75Ti3O12 (BLT) buffer layer of various thickness were fabricated on Pt/TiO2/SiO2/p-Si(100) substrates by rf-magnetron sputtering method. The pure PZT film showed (111) preferential orientation in the XRD patterns, and the PZT/BLT films showed (110) preferential orientation with increasing thickness of the BLT layer. There were no obvious diffraction peaks for the BLT buffer layer, for its thin thickness in PZT/BLT multilayered films. There were the maximum number of largest-size grains in PZT/BLT(30 nm) film among all the samples from the surface images of FESEM. The growth direction and grain size had significant effects on ferroelectric properties of the multilayered films. The fatigue characteristics suggested that 30-nm-thick BLT was just an effective buffer layer enough to alleviate the accumulation of oxygen vacancies near the PZT/BLT interface. The comparison of these results suggests that the buffer layer with an appropriate thickness can improve the ferroelectric properties of multilayered films greatly. Keywords: Ferroelectric thin filmsbuffer layerPbZr0.58Ti0.42O3 Bi3.25La0.75Ti3O12 Acknowledgments This work is supported by the Pre-Research Program of China under Grant No. 513080401, the National Basic Research Program of China under Grant No. 61363Z04.3, and the Key Program of National Nature Science Foundation of China under No. 90407023.