Abstract
High-quality single crystals of perovskite-like (CH3NH3)3Bi2I9 hybrids have been synthesized, using a layered-solution crystal-growth technique. The large dielectric constant is strongly affected by the polar ordering of its constituents. Progressive dipolar ordering of the methylammonium cation upon cooling below 300 K gradually converts the hexagonal structure (space group P63/mmc) into a monoclinic phase (C2/c) at 160 K. A well-pronounced, ferrielectric phase transition at 143 K is governed by in-plane ordering of the bismuth lone pair that breaks inversion symmetry and results in a polar phase (space group P21). The dielectric constant is markedly higher in the C2/c phase above this transition. Here, the bismuth lone pair is disordered in-plane, allowing the polarizability to be substantially enhanced. Density functional theory calculations estimate a large ferroelectric polarization of 7.94 μC/cm(2) along the polar axis in the P21 phase. The calculated polarization has almost equal contributions of the methylammonium and Bi(3+) lone pair, which are fairly decoupled.
Original language | English |
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Pages (from-to) | 33-41 |
Number of pages | 8 |
Journal | Inorganic Chemistry |
Volume | 56 |
Issue number | 1 |
DOIs | |
Publication status | Published - 14-Sept-2016 |
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Dive into the research topics of 'Polar Nature of (CH3NH3)3Bi2I9 Perovskite-Like Hybrids'. Together they form a unique fingerprint.Datasets
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CCDC 1530228: Experimental Crystal Structure Determination
Kamminga, M. (Contributor), Stroppa, A. (Contributor), Picozzi, S. (Contributor), Chislov, M. (Contributor), Zvereva, I. A. (Contributor), Baas, J. (Contributor), Meetsma, A. (Contributor), Blake, G. R. (Contributor) & Palstra, T. T. M. (Contributor), University of Groningen, 30-Jan-2017
DOI: 10.5517/ccdc.csd.cc1ncb6k
Dataset
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CCDC 1530227: Experimental Crystal Structure Determination
Kamminga, M. (Contributor), Stroppa, A. (Contributor), Picozzi, S. (Contributor), Chislov, M. (Contributor), Zvereva, I. A. (Contributor), Baas, J. (Contributor), Meetsma, A. (Contributor), Blake, G. R. (Contributor) & Palstra, T. T. M. (Contributor), University of Groningen, 30-Jan-2017
DOI: 10.5517/ccdc.csd.cc1ncb5j
Dataset
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CCDC 1530229: Experimental Crystal Structure Determination
Kamminga, M. (Contributor), Stroppa, A. (Contributor), Picozzi, S. (Contributor), Chislov, M. (Contributor), Zvereva, I. A. (Contributor), Baas, J. (Contributor), Meetsma, A. (Contributor), Blake, G. R. (Contributor) & Palstra, T. T. M. (Contributor), University of Groningen, 30-Jan-2017
DOI: 10.5517/ccdc.csd.cc1ncb7l
Dataset