Probing intrinsic polarization properties in bismuth-layered ferroelectric films

Authors

• Takayuki Watanabe, Tokyo Institute of Technology, Yokohama Japan
• Hiroshi Funakubo, Tokyo Institute of Technology, Yokohama, Japan
• Minoru Osada, Nanoscale Materials Center, National Institute for Materials Science (NIMS)
• Hiroshi Uchida, Sophia University, Tokyo, Japan
• B. J. Rodriguez, North Carolina State University, RaleighFollow
• Alexei Gruverman, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

March 2007

Comments

Published in Appl. Phys. Lett. 90, 112914 2007. Copyright © 2007 American Institute of Physics. Used by permission.

Abstract

The authors report on an approach to establish intrinsic polarization properties in bismuth-layered ferroelectric films by piezoelectric coefficient and soft-mode spectroscopy, as well as by a direct polarization–electric field hysteresis. In epitaxially grown (Bi_4−xNd_x)Ti₃O₁₂ (0≤x≤0.73) films, they show that these complementary characterizations can phenomenologically and thermodynamically represent the intrinsic polarization states in (Bi_4−xNd_xTi₃O₁₂ films, and the intrinsic P_s of 67 μC/cm² is estimated for pure Bi₄Ti₃O₁₂, superior to 50 μC/cm² in bulk single crystal. Their results provide a pathway to draw full potential in ferroelectric thin films.