Abstract
Elastic anomalies are signatures of phase transitions in condensed matters and have traditionally been studied using various techniques spanning from neutron scattering to static mechanical testing. Here, using band-excitation elastic/piezoresponse spectroscopy, we probed sub-MHz elastic dynamics of a tip bias-induced rhombohedralâ 'tetragonal phase transition of strained (001)-BiFeO 3 (rhombohedral) ferroelectric thin films from â 1/410 3 nm 3 sample volumes. Near this transition, we observed that the Youngâ ™ s modulus intrinsically softens by over 30% coinciding with two-to three-fold enhancement of local piezoresponse. Coupled with phase-field modelling, we also addressed the influence of polarization switching and mesoscopic structural heterogeneities (for example, domain walls) on the kinetics of this phase transition, thereby providing fresh insights into the morphotropic phase boundary in ferroelectrics. Furthermore, the giant electrically tunable elastic stiffness and corresponding electromechanical properties observed here suggest potential applications of BiFeO3 in next-generation frequency-agile electroacoustic devices, based on the utilization of the soft modes underlying successive ferroelectric phase transitions.
| Original language | English |
|---|---|
| Article number | 8985 |
| Journal | Nature Communications |
| Volume | 6 |
| DOIs | |
| State | Published - Nov 24 2015 |
Funding
This work was supported by the US DOE, Basic Energy Sciences, Materials Sciences and Engineering Division through the Office of Science Early Career Research Program (N.B., Q.L.). The experiments were performed at the Center for Nanophase Materials Sciences, which is sponsored at ORNL by the Scientific User Facilities Division, Office of Basic Energy Sciences, US DOE. P.Y. was supported by the National Basic Research Program of China (Grant No. 2015CB921700) and National Natural Science Foundation of China (Grant No. 11274194). L.Q.C. was supported by the US DOE, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Award No. DE-FG02-07ER46417. F.X. was supproted by NSF MRSEC under Grant No. DMR-1420620. Use of the Advanced Photon Source, an Office of Science User Facility operated for the US DOE Office of Science by Argonne National Laboratory, was supported by the US DOE under Contract No. DE-AC02-06CH11357. Q.L. acknowledges helpful discussions with Michael A. Carpenter and Anna N. Morozovska.
| Funders | Funder number |
|---|---|
| NSF MRSEC | |
| Office of Basic Energy Sciences | |
| U.S. Department of Energy | |
| Directorate for Mathematical and Physical Sciences | 1420620 |
| Office of Science | |
| Basic Energy Sciences | |
| Argonne National Laboratory | |
| Oak Ridge National Laboratory | |
| Division of Materials Sciences and Engineering | |
| National Natural Science Foundation of China | 11274194 |
| National Basic Research Program of China (973 Program) | 2015CB921700 |