Acta Materialia, Volume 61, Issue 18, 2013, Pages 6765-6777.
Ja Kyung Lee, Ga Young Shin, Kyung Song, Woo Seok Choi, Yoon Ah Shin, Seong Yong Park, Jason Britson, Ye Cao, Long-Qing Chen, Ho Nyung Lee, Sang Ho Oh.
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), San 31, Pohang 790-784, Republic of Korea and
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA and
Analytical Science Group, Samsung Advanced Institute of Technology (SAIT), Yongin 446-712, Republic of Korea and
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
We report in situ transmission electron microscopy observations of the 180° polarization switching process of a PbZr0.2Ti0.8O3 (PZT) capacitor. The preferential, but asymmetric, nucleation and forward growth of switched c-domains were observed at the PZT/electrode interfaces, arising due to the built-in electric field induced at each interface. The subsequent sideways growth of the switched domains was inhibited by the depolarization field due to the imperfect charge compensation at the counter-electrode and also at the boundaries with preexisting a-domains, which contributed further to the asymmetric switching behavior. It was found that the preexisting a-domains split into fine a- and c-domains constituting a 90° stripe domain pattern during the 180° polarization switching process, revealing that these domains also actively participated in the out-of-plane polarization switching. The real-time observations uncovered the origin of the switching asymmetry and further clarified the importance of charged domain walls and the interfaces with electrodes in the ferroelectric switching processes.