Structure and electrical properties of Na0.5Bi0.5TiO3 ferroelectric thick films derived from a polymer modified sol-gel method

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 58; no. 10; pp. 2042 - 2049
• Main Authors: Hongfen Ji, Wei Ren, Lingyan Wang, Peng Shi, Xiaofeng Chen, Xiaoqing Wu, Xi Yao, Sien-Ting Lau, Qifa Zhou, Shung, K. K.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Annealing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric constant; Dielectric losses; Dielectric thin films; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Physics; Temperature measurement; Thick films; Annealing; Electrical properties; Polymer gels; Perovskites; Layer thickness; Heat treatments; Thin films; Thick film devices; Dielectric polarization; Ferroelectricity; Size effect; Property structure relationship; Permittivity; Sol-gel process
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2011.2054

Lead-free Na 0.5 Bi 0.5 TiO 3 (NBT) ferroelectric thick films were prepared by a poly(vinylpyrrolidone) (PVP) modified sol-gel method. The NBT thick films annealed from 500°C to 750°C exhibit a perovskite structure. The relationship between annealing temperature, thickness, and electrical properties of the thick films has been investigated. The dielectric constants and remnant polarizations of the thick films increase with annealing temperature. The electrical properties of the NBT films show strong thickness dependence. As thickness increases from 1.0 to 4.8 & μm, the dielectric constant of the NBT films increases from 620 to 848, whereas the dielectric loss is nearly independent of the thickness. The remnant polarization of the NBT thick films also increases with increasing thickness. The leakage current density first decreases and then increases with film thickness.