TY - JOUR
KW - Temperature
KW - Electric fields
KW - Polarization
KW - Ferroelectricity
KW - Ferroelectric domains
KW - Vortex flow
KW - Electric-field control
KW - First-order phase transitions
KW - Oxide superlattices
KW - Condensed matter physics
KW - Characterization techniques
KW - Ferroelectric phasis
KW - Nonlinear optical response
KW - Superlattice periods
AU - A.R Damodaran
AU - J.D Clarkson
AU - Z Hong
AU - H B Liu
AU - A.K Yadav
AU - C.T Nelson
AU - S.-L Hsu
AU - M.R McCarter
AU - K.-D Park
AU - V Kravtsov
AU - A Farhan
AU - Y Dong
AU - Z Cai
AU - H Zhou
AU - P Aguado-Puente
AU - P García-Fernández
AU - J Íñiguez
AU - J Junquera
AU - A Scholl
AU - M.B Raschke
AU - L.-Q Chen
AU - D.D Fong
AU - Ramamoorthy Ramesh
AU - L.W Martin
AB - 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 PbTiO"3/SrTiO"3 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. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
BT - Nature Materials
DO - 10.1038/NMAT4951
LA - eng
M1 - 10
N1 - cited By 50
N2 - 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 PbTiO"3/SrTiO"3 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. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
PB - Nature Publishing Group
PY - 2017
SP - 1003
EP - 1009
T2 - Nature Materials
TI - Phase coexistence and electric-field control of toroidal order in oxide superlattices
VL - 16
SN - 14761122
ER -