The effect of cation place exchange on the electrical conductivity of SrBi2M2O9 (M = Ta, Nb)

被引：28

作者：

Palanduz, CA ^{[1
]}

Smyth, DM ^{[1
]}

机构：

[1] Lehigh Univ, Mat Res Ctr, Bethlehem, PA 18015 USA

来源：

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY | 1999年 / 19卷 / 6-7期

关键词：

defects; electrical conductivity; ionic conductivity; tantalates; memories;

D O I：

10.1016/S0955-2219(98)00314-8

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The defect chemistry and charge transport in undoped and doped SrBi2Ta2O9 (SBT) and SrBi2Nb2O9 (SBN) has been studied by measurement of the equilibrium electrical conductivity as a function of oxygen activity at temperatures between 600 and 800 degrees C. Undoped SET appears to contain about 1% excess acceptor centers, while undoped SBN appears to contain about 1% excess donor centers. The behavior is attributed to substantial place exchange between Sr+2 and Bi+3 in the alternating layers of the structure with partial local compensation by oxygen vacancies in the bismuth layers and by electrons in the perovskite-like layers. The total conductivity is then dominated by the better conducting layer, i.e. ionic conductivity by oxygen vacancies in the bismuth layers in SBT, and electron conduction in the perovskite-like layers in SBN. The major determining factor is the larger band gap and greater electron trapping in SET. (C) 1999 Elsevier Science Limited. All rights reserved.

引用

页码：731 / 735

页数：5

共 3 条

[1] Cation disorder in ferroelectric Aurivillius phases of the type Bi(2)ANb(2)O(9) (A=Ba, Sr, Ca) [J].