Diffraction contrast analysis of 90° and 180° ferroelectric domain structures of PbTiO3 thin films

Kenta Aoyagi; Takanori Kiguchi; Yoshitaka Ehara; Tomoaki Yamada; Hiroshi Funakubo; Toyohiko J Konno

doi:10.1088/1468-6996/12/3/034403

Diffraction contrast analysis of 90° and 180° ferroelectric domain structures of PbTiO₃ thin films

Sci Technol Adv Mater. 2011 May 3;12(3):034403. doi: 10.1088/1468-6996/12/3/034403. eCollection 2011 Jun.

Authors

Kenta Aoyagi¹, Takanori Kiguchi², Yoshitaka Ehara³, Tomoaki Yamada⁴, Hiroshi Funakubo³, Toyohiko J Konno²

Affiliations

¹ Department of Materials Science, Tohoku University, Sendai, Miyagi 980-8579, Japan.
² Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577, Japan.
³ Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan.
⁴ Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan.

Abstract

The ferroelectric domain structure of a PbTiO₃ thin film on (100) SrTiO₃ has been investigated by transmission electron microscopy (TEM). Two types of a-domain were found: one extended through the film to the surface and another comprised small a-domains confined within the film. Dark-field TEM (DFTEM) observation revealed that 180° domains formed near the substrate and stopped their growth 100 nm away from the substrate. The DFTEM observation also revealed that 90° domain boundaries had head-to-tail structures. To confirm the polarization direction obtained by experiments, diffracted intensities under a two-beam condition were simulated using the extended Darwin-Howie-Whelan equations. On the basis of the obtained results, a ferroelectric domain structure model of PbTiO₃ thin films on SrTiO₃ is proposed.

Keywords: PbTiO3; TEM; ferroelectric thin film.