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

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.