論文

査読有り
2017年1月

Competing Structural Instabilities in the Ruddlesden Popper Derivatives HRTiO4 (R = Rare Earths): Oxygen Octahedral Rotations Inducing Noncentrosymmetricity and Layer Sliding Retaining Centrosymmetricity

CHEMISTRY OF MATERIALS
  • Arnab Sen Gupta
  • Hirofumi Akamatsu
  • Forrest G. Brown
  • Minh An T. Nguyen
  • Megan E. Strayer
  • Saul Lapidus
  • Suguru Yoshida
  • Koji Fujita
  • Katsuhisa Tanaka
  • Isao Tanaka
  • Thomas E. Mallouk
  • Venkatrarnan Gopalan
  • 全て表示

29
2
開始ページ
656
終了ページ
665
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1021/acs.chemmater.6b04103
出版者・発行元
AMER CHEMICAL SOC

We report the observation of noncentrosymmetricity in the family of HRTiO4 (R = Eu, Gd, Dy) layered oxides possessing a Ruddlesden Popper derivative structure, by second harmonic generation and synchrotron X-ray diffraction with the support of density functional theory calculations. These oxides were previously thought to possess inversion symmetry. Here, inversion symmetry is lifted by rotations of the oxygen-coordinated octahedra, a mechanism that is not active in simple perovskites. We observe a competition between rotations of the oxygen octahedra and sliding of a combined unit of perovskite rocksalt perovskite blocks at the proton layers. For the smaller rare earth ions, R = Eu, Gd, and Dy, which favor the octahedral rotations, noncentrosymmetricity is present but the sliding is absent. For the larger rare earth ions, R = Nd and Sm, the octahedral rotations are absent, but the sliding at the proton layers is present to optimize the length and direction of hydrogen.bonding in the crystal structure. The study reveals a new mechanism for inducing noncentrosymmetricity in layered oxides, and chemical structural effects related to rare earth ion size and hydrogen bonding that can turn this mechanism on and off. We construct a phase diagram of temperature versus rare earth ionic radius for the HRTiO4 family.

リンク情報
DOI
https://doi.org/10.1021/acs.chemmater.6b04103
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000392891700024&DestApp=WOS_CPL
ID情報
  • DOI : 10.1021/acs.chemmater.6b04103
  • ISSN : 0897-4756
  • eISSN : 1520-5002
  • Web of Science ID : WOS:000392891700024

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