Collective nonlinear electric polarization via defect-driven local symmetry breaking

被引：29

作者：

Dong, Wen ^{[1
,2
]}

Cortie, David ^{[1
,3
,4
]}

Lu, Teng ^{[1
]}

Sun, Qingbo ^{[1
]}

Narayanan, Narendirakumar ^{[1
,3
]}

Hu, Wanbiao ^{[1
]}

Jacob, Lilit ^{[5
]}

Li, Qian ^{[6
]}

Yu, Dehong ^{[3
]}

Chen, Hua ^{[7
]}

Chen, Aiping ^{[8
]}

Wei, Xiaoyong ^{[9
,10
]}

Wang, Genmiao ^{[1
]}

Humphrey, Mark G. ^{[1
]}

Frankcombe, Terry J. ^{[5
]}

Liu, Yun ^{[1
]}

机构：

[1] Australian Natl Univ, Res Sch Chem, Canberra, ACT 2601, Australia

[2] Univ Warwick, Dept Phys, Gibbet Hill Rd, Coventry CV4 7AL, W Midlands, England

[3] Australia Nucl Sci & Technol Org, Lucas Height, NSW 2234, Australia

[4] Univ Wollongong, Inst Superconducting & Elect Mat, Innovat Campus,Squires Way, North Wollongong, NSW 2500, Australia

[5] Univ New South Wales, Sch Phys Environm & Math Sci, Canberra, ACT 2601, Australia

[6] Argonne Natl Lab, Adv Photon Source Facil, Lemont, IL 60439 USA

[7] Australian Natl Univ, Ctr Adv Microscopy, Canberra, ACT 2601, Australia

[8] Los Alamos Natl Lab, Ctr Integrated Nanotechnol CINT, Los Alamos, NM 87545 USA

[9] Xi An Jiao Tong Univ, Minist Educ, Key Lab, Elect Mat Res Lab, Xian 710049, Shaanxi, Peoples R China

[10] Xi An Jiao Tong Univ, Int Ctr Dielect Res, Xian 710049, Shaanxi, Peoples R China

来源：

MATERIALS HORIZONS | 2019年 / 6卷 / 08期

基金：

澳大利亚研究理事会;

关键词：

DIELECTRIC-RELAXATION; COLOSSAL PERMITTIVITY; DIPOLE GLASS; MONTE-CARLO; FERROELECTRICITY; BEHAVIOR;

D O I：

10.1039/c9mh00516a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

In this work, we report the defect-mediated, abnormal non-linear polarization behavior observed in centrosymmetric rutile TiO2 where less than 1 at% of sterically mismatched Mg2+ ions are introduced to create ferroelectric-like polarization hysteresis loops. It is found that the defect cluster produces a dipole moment exceeding 6 Debye, with a rotatable component. Such a polarization is further enhanced by the displacement of neighboring Ti4+ ions. The coupling between such defect-driven symmetry-breaking regions generates a collective nonlinear electrical polarization state that persists to high temperatures. More importantly, an observation of abnormal bias shift of polarization hysteresis suggests an antiparallel alignment of certain dipoles frozen relative to the external poling electric field, which is associated with oxygen vacancy hopping. This result challenges the long-standing notion of parallel alignment of dipoles with the external electric field in ferroelectrics. This work also reveals an unexpected new form of non-linear dielectric polarization (non-ferroelectricity) in solid-state materials.

引用

页码：1717 / 1725

页数：9

共 45 条

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