title: Imprint Control of BaTiO3 Thin Films via Chemically Induced Surface Polarization Pinning.
abstract: Surface-adsorbed polar molecules can significantly alter the ferroelectric properties of oxide thin films. Thus, fundamental understanding and controlling the effect of surface adsorbates are crucial for the implementation of ferroelectric thin film devices, such as ferroelectric tunnel junctions. Herein, we report an imprint control of BaTiO3 (BTO) thin films by chemically induced surface polarization pinning in the top few atomic layers of the water-exposed BTO films. Our studies based on synchrotron X-ray scattering and coherent Bragg rod analysis demonstrate that the chemically induced surface polarization is not switchable but reduces the polarization imprint and improves the bistability of ferroelectric phase in BTO tunnel junctions. We conclude that the chemical treatment of ferroelectric thin films with polar molecules may serve as a simple yet powerful strategy to enhance functional properties of ferroelectric tunnel junctions for their practical applications.
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Hyungwoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Tae Heon
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Patzner
authors.affiliation: Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States.
authors.forename: Haidong
authors.initials: H
authors.lastname: Lu
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Wansoo
authors.initials: W
authors.lastname: Chang
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Mahesh K
authors.initials: MK
authors.lastname: Mahanthappa
authors.affiliation: Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States.
authors.forename: Evgeny Y
authors.initials: EY
authors.lastname: Tsymbal
authors.affiliation: Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States.
authors.forename: Alexei
authors.initials: A
authors.lastname: Gruverman
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Chang-Beom
authors.initials: CB
authors.lastname: Eom
keywords: BaTiO3; Imprint control; ferroelectric thin films; ferroelectric tunnel junctions; surface chemistry; water adsorption