Persistence of Ferroelectricity in BaTiO3 through the Insulator-Metal Transition

被引：168

作者：

Kolodiazhnyi, T. ^{[1
]}

Tachibana, M. ^{[1
]}

Kawaji, H. ^{[2
]}

Hwang, J. ^{[3
]}

Takayama-Muromachi, E. ^{[1
]}

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050044, Japan

[2] Tokyo Inst Technol, Mat & Struct Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan

[3] Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea

来源：

PHYSICAL REVIEW LETTERS | 2010年 / 104卷 / 14期

关键词：

D O I：

10.1103/PhysRevLett.104.147602

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The ferroelectric BaTiO3 is a band-gap insulator. Itinerant electrons can be introduced in this material by doping, for example, with oxygen vacancies. Above a critical electron concentration of n(c) approximate to 1 x 10(20) cm(-3). BaTiO3-delta becomes metallic. This immediately raises a question: Does metallic BaTiO3-delta still retain ferroelectricity? One may expect itinerant electrons to destroy ferroelectricity as they screen the long-range Coulomb interactions. We followed the phase transitions in BaTiO3-delta as a function of n far into metallic phase. Although their stability range decreases with n, the low-symmetry phases in metallic BaTiO3-delta are still retained up to an estimated concentration of n* approximate to 1.9 x 10(21) cm(-3). Moreover, it appears that the itinerant electrons partially stabilize the ferroelectric phases in metallic BaTiO3-delta by screening strong crystal field perturbations caused by oxygen vacancies.

引用

页数：4

共 21 条

[1] SYMMETRY CONSIDERATIONS ON MARTENSITIC TRANSFORMATIONS - FERROELECTRIC METALS [J].