title: Studying the Polarization Switching in Polycrystalline BiFeO3 Films by 2D Piezoresponse Force Microscopy.
abstract: For rhombohedral multiferroelectrics, non-180° ferroelectric domain switching may induce ferroelastic and/or (anti-)ferromagnetic effect. So the determination and control of ferroelectric domain switching angles is crucial for nonvolatile information storage and exchange-coupled magnetoelectric devices. We try to study the intrinsic characters of polarization switching in BiFeO3 by introducing a special data processing method to determine the switching angle from 2D PFM (Piezoresponse Force Microscopy) images of randomly oriented samples. The response surface of BiFeO3 is first plotted using the piezoelectric tensor got from first principles calculations. Then from the normalized 2D PFM signals before and after switching, the switching angles of randomly oriented BiFeO3 grains can be determined through numerical calculations. In the polycrystalline BiFeO3 films, up to 34% of all switched area is that with original out-of-plane (OP) polarization parallel to the poling field. 71° polarization switching is more favorable, with the area percentages of 71°, 109° and 180° domain switching being about 42%, 29% and 29%, respectively. Our analysis further reveals that IP stress and charge migration have comparable effect on switching, and they are sensitive to the geometric arrangements. This work helps exploring a route to control polarization switching in BiFeO3, so as to realize desirable magnetoelectric coupling.
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yaming
authors.initials: Y
authors.lastname: Jin
authors.affiliation: 1] National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Physics, China University of Mining and Technology, Xuzhou 221116, People's Republic of China.
authors.forename: Junting
authors.initials: J
authors.lastname: Zhang
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Kan
authors.affiliation: College of Science, Hebei United University, Tangshan 063009, P. R. China.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Bo
authors.affiliation: 1] National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Fengzhen
authors.initials: F
authors.lastname: Huang
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Xu
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Du
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Shuyu
authors.initials: S
authors.lastname: Xiao
authors.affiliation: National Laboratory of Solid State Microstructures and Physics School, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhu