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).

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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