Dielectric relaxations in multiferroic La2Ti2O7 ceramics

被引：22

作者：

Zhang, N. ^{[1
]}

Li, Q. J. ^{[1
]}

Huang, S. G. ^{[1
]}

Yu, Y. ^{[1
]}

Zheng, J. ^{[2
]}

Cheng, C. ^{[2
]}

Wang, C. C. ^{[1
]}

机构：

[1] Anhui Univ, Lab Dielectr Funct Mat, Sch Phys & Mat Sci, Hefei 230601, Peoples R China

[2] Anhui Univ, Ctr Modern Expt Technol, Hefei 230039, Peoples R China

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2015年 / 652卷

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Dielectric property; Electric modulus; Cationic vacancies; Conduction progress; Oxygen vacancies; PIEZOELECTRIC PROPERTIES; LN(2)TI(2)O(7) LN; LA; PYROCHLORE; CONDUCTION; BEHAVIOR;

D O I：

10.1016/j.jallcom.2015.08.169

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

La2Ti2O7 ceramic samples were prepared via conventional solid-state reaction route. The dielectric properties of La2Ti2O7 were investigated as functions of temperature (113-1073 K) and frequency (100 Hz(-1) MHz). Our results revealed that La2Ti2O7 ceramics exhibit intrinsic dielectric response with a dielectric constant of similar to 57 in the temperature range below 250 K. Three thermally activated dielectric relaxations were observed when the temperature higher than 250 K. The low-temperature relaxations R1 with the activation energy of 0.38 eV is found to be a polaron relaxation results from hopping holes. The high-temperature relaxations R2 and R3 are related to the conduction progress associated with the singly and doubly ionized oxygen vacancies, respectively. (C) 2015 Elsevier B.V. All rights reserved.

引用

页码：1 / 8

页数：8

共 41 条

[1] Oxygen-vacancy-related low-frequency dielectric relaxation and electrical conduction in Bi:SrTiO3 [J].

Ang, C ;

Yu, Z ;

Cross, LE .

PHYSICAL REVIEW B, 2000, 62 (01) :228-236

[2] SPACE-CHARGE RELAXATION IN PEROVSKITES [J].

BIDAULT, O ;

GOUX, P ;

KCHIKECH, M ;

BELKAOUMI, M ;

MAGLIONE, M .

PHYSICAL REVIEW B, 1994, 49 (12) :7868-7873

[3] Evidence for oxygen vacancy inducing spontaneous normal-relaxor transition in complex perovskite ferroelectrics [J].

Deng, GC ;

Li, GR ;

Ding, AL ;

Yin, QR .

APPLIED PHYSICS LETTERS, 2005, 87 (19) :1-3

[4] LA2TI2O7 CERAMICS [J].

FUIERER, PA ;

NEWNHAM, RE .

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1991, 74 (11) :2876-2881

[5] Ferroelectricity and giant magnetocapacitance in perovskite rare-earth manganites [J].

Goto, T ;

Kimura, T ;

Lawes, G ;

Ramirez, AP ;

Tokura, Y .

PHYSICAL REVIEW LETTERS, 2004, 92 (25) :257201-1

[6] Relaxor ferroelectricity and colossal magnetocapacitive coupling in ferromagnetic CdCr2S4 [J].

Hemberger, J ;

Lunkenheimer, P ;

Fichtl, R ;

von Nidda, HAK ;

Tsurkan, V ;

Loidl, A .

NATURE, 2005, 434 (7031) :364-367

[7] Dielectric relaxations and dielectric response in multiferroic BiFeO3 ceramics [J].

Hunpratub, Sitchai ;

Thongbai, Prasit ;

Yamwong, Teerapon ;

Yimnirun, Rattikorn ;

Maensiri, Santi .

APPLIED PHYSICS LETTERS, 2009, 94 (06)

[8] Colossal magnetodielectric effects in DyMn2O5 -: art. no. 107207 [J].

Hur, N ;

Park, S ;

Sharma, PA ;

Guha, S ;

Cheong, SW .

PHYSICAL REVIEW LETTERS, 2004, 93 (10) :107207-1

[9] Electronic band structure and photocatalytic activity of Ln2Ti2O7 (Ln = La, Pr, Nd) [J].

Hwang, DW ;

Lee, JS ;

Li, W ;

Oh, SH .

JOURNAL OF PHYSICAL CHEMISTRY B, 2003, 107 (21) :4963-4970

[10] Photocatalytic hydrogen production from water over m-doped La2Ti2O7 (M = Cr, Fe) under visible light irradiation (λ > 420 nm) [J].

Hwang, DW ;

Kirn, HG ;

Lee, JS ;

Kim, J ;

Li, W ;

Oh, SH .

JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (06) :2093-2102

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