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arXiv · 1210.0967

Ferroelectricity Driven by Twisting of Silicate Tetrahedral Chains

Hiroki Taniguchi·Akihide Kuwabara·Jungeun Kim·Younghun Kim·Hiroki Moriwake·Sungwng Kim·Takuya Hoshiyama·Tsukasa Koyama·Shigeo Mori·Masaki Takata·Hideo Hosono·Yoshiyuki Inaguma·Mitsuru Itoh
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Abstract

Conventional perovskite-type ferroelectrics are based on octahedral units of oxygen, and often comprise toxic Pb to achieve robust ferroelectricity. Here, we report the ferroelectricity in a silicate-based compound, Bi2SiO5 (BSO), induced by a structural instability of the corresponding silicate tetrahedral chains. A low-energy phonon mode condenses at ~ 673 K to induce the proper ferroelectric phase transition. Polarization switching was observed in a BSO single crystal with a coercive field of 30 kV/cm and a spontaneous polarization of 0.3 microC/cm2 along a direction normal to the cleavage plane. The in-plane polarization was estimated by first principles calculations to be 23 microC/cm2. The present findings provide a new guideline for designing ferroelectric materials based on SiO4 tetrahedral units, which is ubiquitously found in natural minerals.

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Hiroki Taniguchi, Akihide Kuwabara, Jungeun Kim, Younghun Kim, Hiroki Moriwake, Sungwng Kim, Takuya Hoshiyama, Tsukasa Koyama, Shigeo Mori, Masaki Takata, Hideo Hosono, Yoshiyuki Inaguma, Mitsuru Itoh. 2012-10-03. Ferroelectricity Driven by Twisting of Silicate Tetrahedral Chains. https://arxiv.org/abs/1210.0967

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