Uncovering ferroelectric polarization in tetragonal (Bi1/2K1/2)TiO3-(Bi1/2Na1/2)TiO3 single crystals

Yuuki Kitanaka; Yuji Noguchi; Masaru Miyayama

doi:10.1038/s41598-019-55576-y

Uncovering ferroelectric polarization in tetragonal (Bi_1/2K_1/2)TiO₃-(Bi_1/2Na_1/2)TiO₃ single crystals

Sci Rep. 2019 Dec 17;9(1):19275. doi: 10.1038/s41598-019-55576-y.

Authors

Yuuki Kitanaka¹, Yuji Noguchi², Masaru Miyayama¹

Affiliations

¹ Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan.
² Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan. ynoguchi@fmat.t.u-tokyo.ac.jp.

Abstract

We report the robust ferroelectric properties of (1 - x)(Bi_1/2Na_1/2)TiO₃-x(Bi_1/2K_1/2)TiO₃ (x = 33%) single crystals grown by a top-seeded solution growth process under a high oxygen-pressure (0.9 MPa) atmosphere. The sample exhibit a large remanent polarization of 48 μC/cm² and a sizeable piezoelectric strain constant of 460 pm/V. Neutron powder diffraction structural analysis combined with first-principles calculations reveals that the large ferroelectric polarization comparable to PbTiO₃ stems from the hybridization between Bi-6p and O-2p orbitals at a moderately negative chemical pressure.

Abstract

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