title: Giant elastic tunability in strained BiFeO3 near an electrically induced phase transition.
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 rhombohedral-tetragonal phase transition of strained (001)-BiFeO3 (rhombohedral) ferroelectric thin films from ∼10(3) nm(3) sample volumes. Near this transition, we observed that the Young'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.
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cao
authors.affiliation: State Key Laboratory for Low-Dimensional Quantum Physics, Department of Physics and Collaborative Innovation Center for Quantum Matter, Tsinghua University, Beijing 100084, China.|RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Yu
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Vasudevan
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: N
authors.initials: N
authors.lastname: Laanait
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: A
authors.initials: A
authors.lastname: Tselev
authors.affiliation: Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: F
authors.initials: F
authors.lastname: Xue
authors.affiliation: Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: L Q
authors.initials: LQ
authors.lastname: Chen
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: P
authors.initials: P
authors.lastname: Maksymovych
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Kalinin
authors.affiliation: Center for Nanophase Materials Sciences and Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: N
authors.initials: N
authors.lastname: Balke