Asymmetry in mechanical polarization switching
Abstract
Recent demonstration of a mechanical 180° switching of ferroelectric polarization has enabled an alternative polarization control mechanism based on the flexoelectric coupling between polarization and strain gradient. Mechanical switching is a highly asymmetric phenomenon associated with the inhomogeneous strain induced by an atomic force microscope (AFM) tip pressed against the ferroelectric surface. Here, we demonstrate the asymmetric domain switching behavior in the vicinity of the 180° domain wall in PbTiO3 thin films with respect to the AFM tip scanning direction. The writing-direction-dependent asymmetric domain response has been modeled by molecular dynamics simulation showing asymmetry in domain wall displacement due to the difference in the volume of mechanically switched domains. The obtained results show that the mechanically induced switching dynamics is very different from the conventional 180° switching realized by an external electric field and has to be exploited differently. In particular, nanoscale domain engineering via the tip-induced flexoelectric effect requires careful consideration of asymmetric interaction between the existing domain structures and the strain gradient.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 29, 2017
- Source ID
- 10.1063/1.4983381
Entities
People
- Alexei Gruverman
- Andrew M Rappe
- Haidong Lu
- Hiroshi Funakubo
- Shi Liu
- Shintaro Yasui
- Ziyu Ye
Organizations
- Carnegie Institution for Science
- National Science Foundation
- Office of Naval Research Global
- Tokyo Institute of Technology
- United States Department of Defense
- University of Nebraska–Lincoln
- University of Pennsylvania