ZnTaO2N: Stabilized High-Temperature LiNbO3-Type Structure

Published

November 18, 2016

Author(s)

Yoshinori Kuno, Cedric Tassel, Koji Fujita, Dmitry Batuk, Artem M. Abakumov, Kazuki Shitara, Akihide Kuwabara, Hiroki Moriwake, Daichi Watabe, Clemens Ritter, Craig Brown, Takafumi Yamamoto, Fumitaka Takeiri, Ryu Abe, Yoji Kobayashi, Katsuhisa Tanaka, Hiroshi Kageyama

Abstract

By using a high pressure reaction, we prepared a new oxynitride ZnToO₂N that crystallizes in a centrosymmetric (R-3_c)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 non-centrosymmetric (R3_c) 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 covalent nature of Zn, as well as the high valent Ta⁵⁺ ion, is responisblefor the stabilization of HTLN-type structure, affording a novel quasi-triangular ZnO₂N coordination. Interestingly, only 3% of 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.

Citation

Journal of the American Chemical Society

Volume

138

Issue

49

Pub Type

Journals

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Keywords

neutron diffraction, x-ray diffraction, structure, oxynitride

Citation

Kuno, Y. , Tassel, C. , Fujita, K. , Batuk, D. , Abakumov, A. , Shitara, K. , Kuwabara, A. , Moriwake, H. , Watabe, D. , Ritter, C. , Brown, C. , Yamamoto, T. , Takeiri, F. , Abe, R. , Kobayashi, Y. , Tanaka, K. and Kageyama, H. (2016), ZnTaO₂N: Stabilized High-Temperature LiNbO₃-Type Structure, Journal of the American Chemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922359 (Accessed October 13, 2024)