title: ZnTaO2N: Stabilized High-Temperature LiNbO3-type Structure.
abstract: By using a high-pressure reaction, we prepared a new oxynitride ZnTaO2N that crystallizes in a centrosymmetric (R3̅c) high-temperature LiNbO3-type structure (HTLN-type). The stabilization of the HTLN-type structure down to low temperatures (at least 20 K) makes it possible to investigate not only the stability of this phase, but also the phase transition to a noncentrosymmetric (R3c) LiNbO3-type structure (LN-type) which is yet to be clarified. Synchrotron and neutron diffraction studies in combination with transmission electron microscopy show that Zn is located at a disordered 12c site instead of 6a, implying an order-disorder mechanism of the phase transition. It is found that the closed d-shell of Zn2+, as well as the high-valent Ta5+ion, is responsible for the stabilization of the HTLN-type structure, affording a novel quasitriangular ZnO2N coordination. Interestingly, only 3% Zn substitution for MnTaO2N induces a phase transition from LN- to HTLN-type structure, implying the proximity in energy between the two structural types, which is supported by the first-principles calculations.
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kuno
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.|The Hakubi Center for Advanced Research, Kyoto University , Kyoto 606-8501, Japan.
authors.forename: Cédric
authors.initials: C
authors.lastname: Tassel
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Batuk
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerpen, Belgium.|Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology , Nobel Str. 3, 143026 Moscow, Russia.
authors.forename: Artem M
authors.initials: AM
authors.lastname: Abakumov
authors.affiliation: Nanostructures Research Laboratory , Nagoya 456-8587, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Shitara
authors.affiliation: Nanostructures Research Laboratory , Nagoya 456-8587, Japan.
authors.forename: Akihide
authors.initials: A
authors.lastname: Kuwabara
authors.affiliation: Nanostructures Research Laboratory , Nagoya 456-8587, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Moriwake
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Watabe
authors.affiliation: Institute Laue-Langevin , 71 Avenue des Martyrs, 38000 Grenoble, France.
authors.forename: Clemens
authors.initials: C
authors.lastname: Ritter
authors.affiliation: Center for Neutron Research, National Institute of Standards and Technology (NIST) , Gaithersburg, Maryland 20899, United States.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Brown
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Takeiri
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Abe
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.|CREST, Japan Science and Technology Agency (JST) , Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kageyama