Phase coexistence and electric-field control of toroidal order in oxide superlattices

ABSTRACT Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by

applying a range of characterization techniques, and simulations, we observe that in PbTiO3/SrTiO3 superlattices all of these effects can be found. By exploring superlattice period-,

temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase

transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric _a_1/_a_2 phase. At room temperature, the coexisting vortex and

ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding

ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this

mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our

findings suggest new cross-coupled functionalities. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS

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Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS NON-EQUILIBRIUM PATHWAYS TO EMERGENT POLAR SUPERTEXTURES Article 24 September 2024 LOCAL NEGATIVE PERMITTIVITY AND TOPOLOGICAL

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ACKNOWLEDGEMENTS A.R.D. acknowledges support from the Army Research Office under grant W911NF-14-1-0104 and the Department of Energy, Office of Science, Office of Basic Energy Sciences under

grant no. DE-SC0012375 for synthesis and structural study of the materials. Z.H. acknowledges support from NSF-MRSEC grant number DMR-1420620 and NSF-MWN grant number DMR-1210588. A.K.Y.

acknowledges support from the Office of Basic Energy Sciences, US Department of Energy DE-AC02-05CH11231. C.T.N. acknowledge support from the Office of Basic Energy Sciences, US Department

of Energy DE-AC02-05CH11231. S.L.H. acknowledges support from the National Science Foundation under the MRSEC programme (DMR-1420620). M.R.M. acknowledges support from the National Science

Foundation Graduate Research Fellowship under grant number DGE-1106400. K.-D.P., V.K. and M.B.R. acknowledge support from the US Department of Energy, Office of Basic Sciences, Division of

Material Sciences and Engineering, under Award No. DE-SC0008807. A.F. acknowledges support from the Swiss National Science Foundation. P.G.-F. and J.J. acknowledge financial support from the

Spanish Ministry of Economy and Competitiveness through grant number FIS2015-64886-C5-2-P.J.Í. is supported by the Luxembourg National Research Fund (Grant FNR/C15/MS/10458889 NEWALLS).

L.-Q.C. is supported by the US Department of Energy, Office of Basic Energy Sciences under Award FG02-07ER46417. R.R. and L.W.M. acknowledge support from the Gordon and Betty Moore

Foundation’s EPiQS Initiative, under grant GBMF5307. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of

Energy under Contract No. DE-AC02-05CH11231. Nanodiffraction measurements were supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials

Sciences and Engineering Division. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of

Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Electron microscopy of superlattice structures was performed at the Molecular Foundry at Lawrence Berkeley

National Laboratory, supported by the Office of Science, Office of Basic Energy Sciences, US Department of Energy (DE-AC02-05CH11231). AUTHOR INFORMATION Author notes * A. R. Damodaran and

J. D. Clarkson: These authors contributed equally to this work. AUTHORS AND AFFILIATIONS * Department of Materials Science and Engineering, University of California, Berkeley, California,

94720, USA A. R. Damodaran, J. D. Clarkson, A. K. Yadav, C. T. Nelson, S.-L. Hsu, R. Ramesh & L. W. Martin * Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley,

California, 94720, USA A. R. Damodaran, J. D. Clarkson, A. K. Yadav, R. Ramesh & L. W. Martin * Department of Materials Science and Engineering, Pennsylvania State University, State

College, Pennsylvania, 16802, USA Z. Hong & L.-Q. Chen * Materials Science Division, Argonne National Laboratory, Argonne, Illinois, 60439, USA H. Liu, Y. Dong & D. D. Fong * School

of Electrical Engineering and Computer Science, UC Berkeley, Berkeley, California, 94720, USA A. K. Yadav * National Center for Electron Microscopy, Lawrence Berkeley National Laboratory,

Berkeley, California, 94720, USA C. T. Nelson & S.-L. Hsu * Department of Physics, University of California, Berkeley, Berkeley, California, 94720, USA M. R. McCarter & R. Ramesh *

Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado, 80309, USA K.-D. Park, V. Kravtsov & M. B. Raschke * Advanced Light Source,

Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA A. Farhan & A. Scholl * X-ray Science Division, Argonne National Laboratory, Argonne, Illinois, 60439, USA Z. Cai 

& H. Zhou * Centro de Física de Materiales, Universidad del País Vasco, 20018 San Sebastián, Spain P. Aguado-Puente * Donostia International Physics Center, 20018 San Sebastián, Spain P.

Aguado-Puente * Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, avenida de los Castros s/n, 39005

Santander, Spain P. García-Fernández & J. Junquera * Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux,

L-4362 Esch/Alzette, Luxembourg J. Íñiguez Authors * A. R. Damodaran View author publications You can also search for this author inPubMed Google Scholar * J. D. Clarkson View author

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You can also search for this author inPubMed Google Scholar * L. W. Martin View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS A.R.D., J.D.C.,

R.R. and L.W.M. conceived of the central concepts and designed the experiments. A.R.D., H.L. and M.R.M. conducted the synchrotron and laboratory X-ray diffraction studies. J.D.C. and A.R.D.

conducted the scanning probe-based PFM measurements. Z.H. performed and analysed the phase-field simulations. A.K.Y. and M.R.M. synthesized the materials. C.T.N. and S.L.H. performed the

TEM-based characterization of the superlattice samples, along with the detailed polarization vector analysis. K.-D.P. and V.K. performed the near- and far-field SHG measurements. A.F.

conducted the PEEM measurements. Y.D., Z.C., H.Z. and H.L. conducted the synchrotron nanodiffraction studies. P.A.-P. and J.J. completed the second-principles simulations that were analysed

by P.A.-P., P.G.-F., J.Í. and J.J. A.S., M.B.R., L.-Q.C. and D.D.F. contributed to analysis, discussions, and understanding of the data and the development of the manuscript. A.R.D., R.R.

and L.W.M. wrote the manuscript. All authors discussed the results and implications of the work and read, edited and commented on the manuscript at all stages. CORRESPONDING AUTHOR

Correspondence to L. W. Martin. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial interests. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION

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and electric-field control of toroidal order in oxide superlattices. _Nature Mater_ 16, 1003–1009 (2017). https://doi.org/10.1038/nmat4951 Download citation * Received: 17 December 2016 *

Accepted: 28 June 2017 * Published: 07 August 2017 * Issue Date: 01 October 2017 * DOI: https://doi.org/10.1038/nmat4951 SHARE THIS ARTICLE Anyone you share the following link with will be

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