The switching of domains in ferroelectric and multiferroic materials plays a central role in their application to next-generation computer systems, sensing applications, and memory storage. A detailed understanding of the response to electric fields and the switching behavior in the presence of complex domain structures and extrinsic effects (e.g., defects and dislocations) is crucial for the design of improved ferroelectrics. In this work, in situ transmission electron microscopy is coupled with atomistic molecular dynamics simulations to explore the response of 71° ferroelastic domain walls in BiFeO3 with various orientations under applied electric-field excitation. We observe that 71° domain walls can have intrinsically asymmetric responses to opposing biases. In particular, when the electric field has a component normal to the domain wall, forward and backward domain-wall velocities can be dramatically different for equal and opposite fields. Additionally, the presence of defects and dislocations can strongly affect the local switching behaviors through pinning or nucleation of the domain walls. These results offer insight for controlled ferroelastic domain manipulation via electric-field engineering.
Bibliographical noteFunding Information:
M.L.T., M.L.J., and C.R.W. acknowledge support of the Office of Naval Research under Contract N00014-1101-0296. S.L. acknowledges support from the National Science Foundation under Grant DMR-1124696 and support from the Carnegie Institution for Science. I.G. acknowledges support from the Office of Naval Research under Grant N00014-12-1-1033. A.R.D. acknowledges support from the Army Research Office under Grant W911NF-14-1-0104. L.W.M. acknowledges support from the National Science Foundation under Grant DMR-1451219. A.M.R. acknowledges support from the Department of Energy under Grant DE-FG02-07ER46431. Aberration-corrected TEM experiments were performed in the Argonne National Laboratory?s Electron Microscopy Center, supported by the Department of Energy?s Office of Science. Electron microscopy experiments were conducted in Drexel University?s Centralized Research Facilities. Computational support was provided by the High Performance Computing Modernization Program (HPCMO) of the U.S. DoD and by the National Energy Research Scientific Computing Center of the Department of Energy.
© 2015 American Chemical Society.
- bismuth ferrite
- domain switching
- in situ