title: Atomic mechanism of polarization-controlled surface reconstruction in ferroelectric thin films.
abstract: At the ferroelectric surface, the broken translational symmetry induced bound charge should significantly alter the local atomic configurations. Experimentally revealing the atomic structure of ferroelectric surface, however, is very challenging due to the strong spatial variety between nano-sized domains, and strong interactions between the polarization and other structural parameters. Here, we study surface structures of Pb(Zr0.2Ti0.8)O3 thin film by using the annular bright-field imaging. We find that six atomic layers with suppressed polarization and a charged 180° domain wall are at negatively poled surfaces, no reconstruction exists at positively poled surfaces, and seven atomic layers with suppressed polarization and a charged 90° domain wall exist at nominally neutral surfaces in ferroelastic domains. Our results provide critical insights into engineering ferroelectric thin films, fine grain ceramics and surface chemistry devices. The state-of-the-art methodology demonstrated here can greatly advance our understanding of surface science for oxides.
authors.affiliation: Electron Microscopy Laboratory, School of Physics, Center for Nanochemistry, Peking University, Beijing 100871, China.|Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
authors.forename: Peng
authors.identifier: http://orcid.org/0000-0001-9868-2115
authors.initials: P
authors.lastname: Gao
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, China.
authors.forename: Heng-Jui
authors.initials: HJ
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, China.
authors.forename: Yen-Lin
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, China.|Institute of Physics, Academia Sinica, Taipei, Taiwan 105, China.
authors.forename: Ying-Hao
authors.initials: YH
authors.lastname: Chu
authors.affiliation: Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Ryo
authors.identifier: http://orcid.org/0000-0001-5801-0971
authors.initials: R
authors.lastname: Ishikawa
authors.affiliation: Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Bin
authors.identifier: http://orcid.org/0000-0002-4306-2979
authors.initials: B
authors.lastname: Feng
authors.affiliation: Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.|International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors.forename: Ying
authors.identifier: http://orcid.org/0000-0002-6887-5503
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.|International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors.forename: En-Ge
authors.initials: EG
authors.lastname: Wang
authors.affiliation: Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan.|Nanostructures Research Laboratory, Japan Fine Ceramic Center, Nagoya 456-8587, Japan.|WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ikuhara