### Abstract

Spontaneous polarizations (P_{S}’s) of BaTiO_{3} and SrTiO_{3} under various conditions are calculated ab initio using different exchange-correlation functionals. The extensive theoretical sets of P_{S} vs. ion positions are found to lie on a single curve, despite the chemical differences and the wide variations of P_{S} and lattice parameters. This uncovers accurate simple analytical formulas of P_{S} of SrTiO_{3}-BaTiO_{3} system expressed by ion positions; a single formula predicts both macroscopic and atomic-scale P_{S} of SrTiO_{3}, BaTiO_{3} and SrTiO_{3}-BaTiO alloys. The accuracy of the formula is demonstrated by the application to experiments, BaTiO_{3}-SrTiO_{3} (-CaTiO_{3}) alloys, Sr_{4}Ti_{4}O_{12} with P_{S} // a-axis, a parallel domain, and a headon domain. In addition, the present results verify empirically that oxygen displacement is the primary identifier and the origin of P_{S} of SrTiO_{3} and BaTiO_{3} and indicate that BaTiO_{3} and SrTiO_{3} may transforms into new state by an extremely large strain, e.g., −3%. Furthermore, the earlier prediction of headon domain without aid of defects was confirmed. The present procedures for finding formulas can be applied to other materials.

Original language | English |
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Pages (from-to) | 315-323 |

Number of pages | 9 |

Journal | Computational Materials Science |

Volume | 158 |

DOIs | |

Publication status | Published - Feb 15 2019 |

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### All Science Journal Classification (ASJC) codes

- Computer Science(all)
- Chemistry(all)
- Materials Science(all)
- Mechanics of Materials
- Physics and Astronomy(all)
- Computational Mathematics

### Cite this

**Accurate semiempirical analytical formulas for spontaneous polarization by crystallographic parameters of SrTiO _{3}-BaTiO_{3} system by ab initio calculations.** / Watanabe, Yukio.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Accurate semiempirical analytical formulas for spontaneous polarization by crystallographic parameters of SrTiO3-BaTiO3 system by ab initio calculations

AU - Watanabe, Yukio

PY - 2019/2/15

Y1 - 2019/2/15

N2 - Spontaneous polarizations (PS’s) of BaTiO3 and SrTiO3 under various conditions are calculated ab initio using different exchange-correlation functionals. The extensive theoretical sets of PS vs. ion positions are found to lie on a single curve, despite the chemical differences and the wide variations of PS and lattice parameters. This uncovers accurate simple analytical formulas of PS of SrTiO3-BaTiO3 system expressed by ion positions; a single formula predicts both macroscopic and atomic-scale PS of SrTiO3, BaTiO3 and SrTiO3-BaTiO alloys. The accuracy of the formula is demonstrated by the application to experiments, BaTiO3-SrTiO3 (-CaTiO3) alloys, Sr4Ti4O12 with PS // a-axis, a parallel domain, and a headon domain. In addition, the present results verify empirically that oxygen displacement is the primary identifier and the origin of PS of SrTiO3 and BaTiO3 and indicate that BaTiO3 and SrTiO3 may transforms into new state by an extremely large strain, e.g., −3%. Furthermore, the earlier prediction of headon domain without aid of defects was confirmed. The present procedures for finding formulas can be applied to other materials.

AB - Spontaneous polarizations (PS’s) of BaTiO3 and SrTiO3 under various conditions are calculated ab initio using different exchange-correlation functionals. The extensive theoretical sets of PS vs. ion positions are found to lie on a single curve, despite the chemical differences and the wide variations of PS and lattice parameters. This uncovers accurate simple analytical formulas of PS of SrTiO3-BaTiO3 system expressed by ion positions; a single formula predicts both macroscopic and atomic-scale PS of SrTiO3, BaTiO3 and SrTiO3-BaTiO alloys. The accuracy of the formula is demonstrated by the application to experiments, BaTiO3-SrTiO3 (-CaTiO3) alloys, Sr4Ti4O12 with PS // a-axis, a parallel domain, and a headon domain. In addition, the present results verify empirically that oxygen displacement is the primary identifier and the origin of PS of SrTiO3 and BaTiO3 and indicate that BaTiO3 and SrTiO3 may transforms into new state by an extremely large strain, e.g., −3%. Furthermore, the earlier prediction of headon domain without aid of defects was confirmed. The present procedures for finding formulas can be applied to other materials.

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U2 - 10.1016/j.commatsci.2018.11.043

DO - 10.1016/j.commatsci.2018.11.043

M3 - Article

VL - 158

SP - 315

EP - 323

JO - Computational Materials Science

JF - Computational Materials Science

SN - 0927-0256

ER -