Monoclinic ferroelectric NaNbO3 at room temperature: Crystal structure solved by using super high resolution neutron powder diffraction

被引：23

作者：

Cheon, C. I. ^{[1
]}

Joo, H. W. ^{[1
]}

Chae, K-W. ^{[1
]}

Kim, J. S. ^{[2
]}

Lee, S. H. ^{[3
]}

Torii, S. ^{[3
,4
]}

Kamiyama, T. ^{[3
,4
,5
]}

机构：

[1] Hoseo Univ, Dept Mat Sci & Engn, Chungnam Do 336795, South Korea

[2] Hoseo Univ, Dept Digital Display Engn, Chungnam Do 336795, South Korea

[3] KEK, Inst Mat Struct Sci, Tokai, Ibaraki 3191106, Japan

[4] KEK, J PARC Ctr, Tokai, Ibaraki 3191106, Japan

[5] Grad Univ Adv Studies Sokendai, Tokai, Ibaraki 3191106, Japan

来源：

MATERIALS LETTERS | 2015年 / 156卷

关键词：

Crystal structure; Monoclinic; Ferroelectric; NaNbO3; Super high resolution; PHASE-TRANSITION; X-RAY; RAMAN;

D O I：

10.1016/j.matlet.2015.05.075

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The crystal structure of NaNbO3 at ambient temperature was solved using time-off-flight neutron data obtained from Super High Resolution Neutron Powder Diffractometer in J-PARC. The solved structure was a novel monoclinic type with the space group Pin and lattice parameters of a=5.50453(1), b=15.52975 (3), c=5.56779(1) angstrom, and beta=90.0645(2)degrees. Bond valence calculation indicates that the solved structure is chemically valid. This solved structure corresponds with the observed ferroelectric behaviors (P-s= 11-25 mu C/cm(2), S=0.03-0.04%). The calculated P-s (similar to 21 mu C/cm(2)) using the refined atomic parameters for one-quarter unit cell conform well to the observed value. Cooperative NbO6 octahedral tilting accompanied by the phase transition from the parent structure Pcmb to the Pm mainly contributes to the spontaneous polarization. (C) 2015 Elsevier B.V. All rights reserved.

引用

页码：214 / 219

页数：6

共 26 条

[1] FERROELECTRIC BEHAVIOR AND PHASE-TRANSITION AT 715-K IN SRAIF5 [J].