title: Ferroelectric translational antiphase boundaries in nonpolar materials.
abstract: Ferroelectric materials are heavily used in electro-mechanics and electronics. Inside the ferroelectric, domain walls separate regions in which the spontaneous polarization is differently oriented. Properties of ferroelectric domain walls can differ from those of the domains themselves, leading to new exploitable phenomena. Even more exciting is that a non-ferroelectric material may have domain boundaries that are ferroelectric. Many materials possess translational antiphase boundaries. Such boundaries could be interesting entities to carry information if they were ferroelectric. Here we show first that antiphase boundaries in antiferroelectrics may possess ferroelectricity. We then identify these boundaries in the classical antiferroelectric lead zirconate and evidence their polarity by electron microscopy using negative spherical-aberration imaging technique. Ab initio modelling confirms the polar bi-stable nature of the walls. Ferroelectric antiphase boundaries could make high-density non-volatile memory; in comparison with the magnetic domain wall memory, they do not require current for operation and are an order of magnitude thinner.
authors.affiliation: 1] Ceramics Laboratory, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne CH-1015, Switzerland [2] Peter Grünberg Institute and Ernst Ruska Center for Microscopy and Spectroscopy with Electrons, Research Center Jülich, 52425 Jülich, Germany.
authors.forename: Xian-Kui
authors.initials: XK
authors.lastname: Wei
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Tagantsev
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kvasov
authors.affiliation: Institute of Physics, University of Silesia, Katowice 40007, Poland.
authors.forename: Krystian
authors.initials: K
authors.lastname: Roleder
authors.affiliation: 1] Peter Grünberg Institute and Ernst Ruska Center for Microscopy and Spectroscopy with Electrons, Research Center Jülich, 52425 Jülich, Germany [2] International Centre of Dielectric Research, The School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Chun-Lin
authors.initials: CL
authors.lastname: Jia
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne CH-1015, Switzerland.
authors.forename: Nava
authors.initials: N
authors.lastname: Setter