title: Highly mobile ferroelastic domain walls in compositionally graded ferroelectric thin films.
abstract: Domains and domain walls are critical in determining the response of ferroelectrics, and the ability to controllably create, annihilate, or move domains is essential to enable a range of next-generation devices. Whereas electric-field control has been demonstrated for ferroelectric 180° domain walls, similar control of ferroelastic domains has not been achieved. Here, using controlled composition and strain gradients, we demonstrate deterministic control of ferroelastic domains that are rendered highly mobile in a controlled and reversible manner. Through a combination of thin-film growth, transmission-electron-microscopy-based nanobeam diffraction and nanoscale band-excitation switching spectroscopy, we show that strain gradients in compositionally graded PbZr1-xTixO3 heterostructures stabilize needle-like ferroelastic domains that terminate inside the film. These needle-like domains are highly labile in the out-of-plane direction under applied electric fields, producing a locally enhanced piezoresponse. This work demonstrates the efficacy of novel modes of epitaxy in providing new modalities of domain engineering and potential for as-yet-unrealized nanoscale functional devices.
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.|Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Agar
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Damodaran
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Okatan
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.|National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kacher
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.|National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: C
authors.initials: C
authors.lastname: Gammer
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Vasudevan
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: S
authors.initials: S
authors.lastname: Pandya
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: L R
authors.initials: LR
authors.lastname: Dedon
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: R V K
authors.initials: RV
authors.lastname: Mangalam
authors.affiliation: Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Velarde
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: S
authors.initials: S
authors.lastname: Jesse
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: N
authors.initials: N
authors.lastname: Balke
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.|National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Minor
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: S V
authors.identifier: 0000-0001-5354-6152
authors.initials: SV
authors.lastname: Kalinin
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.|Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: L W
authors.initials: LW
authors.lastname: Martin