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arXiv · 1906.07501

Weak Ferroelectricity in n = 2 pseudo Ruddlesden-Popper-type niobate Li2SrNb2O7

Takayuki Nagai·Hirokazu Shirakuni·Akitoshi Nakano·Hiroshi Sawa·Hiroki Moriwake·Ichiro Terasaki·Hiroki Taniguchi
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Abstract

Li2SrNb2O7 (LSNO) crystallizes in a structure closely related to n = 2 Ruddlesden-Popper-type compounds, which is gen-erally formed by intergrowth of 2-dimensional perovskite-type blocks and rocksalt-type layers. The present study demonstrates a coexistence of spontaneous polarization and anti-ferroelectric-like nonlinear response in LSNO at 80 K, suggesting a weak ferroelectricity below the phase transition temperature of 217 K. A combination of first-principles cal-culations and single crystal x-ray diffractions clarifies a polar P21cn structure for the ground state of LSNO, where an in-plane anti-ferroelectric displacement and an out-of-plane polar shift simultaneously take place. The present study offers a new perspective to design ferroelectric and antiferroelectric materials with Ruddlesden-Popper-type compounds.

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Takayuki Nagai, Hirokazu Shirakuni, Akitoshi Nakano, Hiroshi Sawa, Hiroki Moriwake, Ichiro Terasaki, Hiroki Taniguchi. 2019-06-18. Weak Ferroelectricity in n = 2 pseudo Ruddlesden-Popper-type niobate Li2SrNb2O7. https://arxiv.org/abs/1906.07501

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