Electronic Ferroelectricity in a Molecular Crystal with Large Polarization Directing Antiparallel to Ionic Displacement

被引：193

作者：

Kobayashi, Kensuke ^{[1
,2
]}

Horiuchi, Sachio ^{[3
,4
]}

Kumai, Reiji ^{[1
,2
,3
]}

Kagawa, Fumitaka ^{[4
,5
]}

Murakami, Youichi ^{[1
,2
]}

Tokura, Yoshinori ^{[3
,5
,6
,7
]}

机构：

[1] High Energy Accelerator Res Org KEK, CMRC, Tsukuba, Ibaraki 3050801, Japan

[2] High Energy Accelerator Res Org KEK, Photon Factory, Inst Mat Struct Sci, Tsukuba, Ibaraki 3050801, Japan

[3] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058562, Japan

[4] Japan Sci & Technol Agcy JST, CREST, Tokyo 1020076, Japan

[5] Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan

[6] ASI RIKEN, CERG, Wako, Saitama 3510198, Japan

[7] ASI RIKEN, Cross Correlated Mat Res Grp CMRG, Wako, Saitama 3510198, Japan

来源：

PHYSICAL REVIEW LETTERS | 2012年 / 108卷 / 23期

基金：

日本学术振兴会;

关键词：

TETRATHIAFULVALENE-PARA-CHLORANIL; CHARGE-TRANSFER COMPLEX; DIELECTRIC RESPONSE; PHASE-TRANSITION; TTF-CA;

D O I：

10.1103/PhysRevLett.108.237601

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Ferroelectric polarization of 6.3 mu C cm(-2) is induced by the neutral-to-ionic transition, upon which nonpolar molecules of electron donor tetrathiafulvalene (TTF) and acceptor p-chloranil (CA) are incompletely ionized to +/-0.60e and dimerized along the molecular stacking chain. We find that the ferroelectric properties are governed by intermolecular charge transfer rather than simple displacement of static point charge on molecules. The observed polarization and poling effect on the absolute structural configuration can be interpreted in terms of electronic ferroelectricity, which not only exhibits antiparallel polarity to the ionic displacement but also enhances the polarization more than 20 times that of the point-charge model.

引用

页数：5

共 32 条

[21] MIXED REGULAR STACK CHARGE-TRANSFER CRYSTALS - FUNDAMENTAL MICROSCOPIC PARAMETERS FROM OPTICAL-SPECTRA [J].