Is hexagonal InMnO$_3$ ferroelectric?

ORAL

Abstract

Hexagonal manganite (h-REMnO$_3$; RE=rare earths) shows a unique improper ferroelectricity, accompanying a structural trimerization. RE can be replaced by In, which is much smaller than any RE ions. Recently, Oak {\it{et al.}} [1] suggested InMnO$_3$ is ferroelectric from the results of first-principles calculations, while Kumagai {\it{et al.}} [2] proposed a non-ferroelectric ground state. In this talk, we will report the results of our investigation on the structural domains and local structural distortions of InMnO$_3$ using dark-field transmission electron microscopy. We demonstrate that InMnO$_3$ shows a distinct $\sqrt{3}\times\sqrt{3}$-type superstructure from the high-temperature paraelectric phase (P6$_3$/mmc), and the domain structure can be delicately controlled by varying the synthesis and annealing conditions. The correlation between physical properties and local structural distortions in the InMnO$_3$ will be discussed in detail. [1] M.-A. Oak, J.-H. Lee, H. M. Jang, J. S. Goh, H. J. Choi and J. F. Scott, PRL \textbf{106}, 047601 (2011). [2] Y. Kumagai, A. A. Belik, M. Lilienblum, N. Leo, M. Fiebig, and N. A. Spaldin, PRB \textbf{85}, 174422 (2012).

–

Authors

  • Fei-Ting Huang

    • Department of Physics and Astronomy, Rutgers University

  • Y. Horibe

    • Department of Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials, and Department of Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University

  • Xueyun Wang

    • Department of Physics and Astronomy, Rutgers University

  • S.-W. Cheong

    • RCEM/Dept. of Physics and Astronomy, Rutgers Univ.
    • Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers U., NJ, USA
    • Department of Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University

  • Shigeo Mori

    • Department of Materials Science, Osaka Prefecture University
    • Department of Materials Science, Osaka Predecture University