Nanodomain Engineering in Ferroelectric Capacitors with Graphene Electrodes.
Polarization switching in ferroelectric capacitors is typically realized by application of an electrical bias to the capacitor electrodes and occurs via a complex process of domain structure reorganization. As the domain evolution in real devices is governed by the distribution of the nucleation centers, obtaining a domain structure of a desired configuration by electrical pulsing is challenging, if not impossible. Recent discovery of polarization reversal via the flexoelectric effect has opened a possibility for deterministic control of polarization in ferroelectric capacitors. In this paper, we demonstrate mechanical writing of arbitrary-shaped nanoscale domains in thin-film ferroelectric capacitors with graphene electrodes facilitated by a strain gradient induced by a tip of an atomic force microscope (AFM). A phase-field modeling prediction of a strong effect of graphene thickness on the threshold load required to initiate mechanical switching has been confirmed experimentally. Deliberate voltage-free domain writing represents a viable approach for development of functional devices based on domain topology and electronic properties of the domains and domain walls.
Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States.
Haidong
H
Lu
Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
Bo
B
Wang
Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States.
Tao
T
Li
Department of Chemistry, University of Nebraska , Lincoln, Nebraska 68588, United States.
Alexey
A
Lipatov
Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
Hyungwoo
H
Lee
Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States.
Anil
A
Rajapitamahuni
Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
Ruijuan
R
Xu
Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States.
Xia
X
Hong
Zernike Institute for Advanced Materials, University of Groningen , 9747 AG Groningen, The Netherlands.
Saeedeh
S
Farokhipoor
Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.|Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Lane W
LW
Martin
Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
Chang-Beom
CB
Eom
Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
Long-Qing
LQ
Chen
Department of Chemistry, University of Nebraska , Lincoln, Nebraska 68588, United States.|Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States.
Alexander
A
Sinitskii
Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States.|Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States.
Alexei
A
Gruverman
Flexoelectric switching; domain engineering; ferroelectric films; graphene