Electrical conductivity and defect chemistry of BaxSr1-xCoyFe1-yO3-δ perovskites

被引：0

作者：

Yang, Zhen ^{[1
]}

Harvey, Ashley S. ^{[1
]}

Infortuna, Anna ^{[1
]}

Schoonman, Joop ^{[2
]}

Gauckler, Ludwig J. ^{[1
]}

机构：

[1] ETH, Dept Mat, CH-8093 Zurich, Switzerland

[2] Delft Univ Technol, Sect Mat Energy Convers & Storage, Dept Chem Engn, NL-2628 BL Delft, Netherlands

来源：

JOURNAL OF SOLID STATE ELECTROCHEMISTRY | 2011年 / 15卷 / 02期

基金：

瑞士国家科学基金会;

关键词：

Electrical conductivity; BSCF; Mixed ionic and electronic conduction; Perovskite; Metal-insulator transition; Cathode; Solid oxide fuel cell; Catalysis; OXIDE FUEL-CELLS; CATHODE MATERIAL; OXYGEN STOICHIOMETRY; CRYSTAL-STRUCTURE; BA0.5SR0.5CO0.8FE0.2O3-DELTA; PERMEATION; STABILITY; MEMBRANES; SYSTEM; CO;

D O I：

10.1007/s10008-010-1208-4

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

Bulk Ba(x)Sr(1-x)CoyFe(1-y)O(3-delta) compositions (BSCF) were synthesized by the solid-state reaction method. The electrical conductivity of ceramic bars was measured using a dc four-probe method as a function of temperature in air up to 970 A degrees C. All compositions showed thermally activated p-type semi-conductivity up to similar to 450 A degrees C and then a transition to metal-like conductivity. The small-polaron hopping p-type semi-conductivity depends on the oxygen nonstoichiometry, which increases with increasing temperature. Metal-like conductivity is attributed to the overlap of the transition metal d-electron orbitals with the oxygen p-orbitals. Strontium-rich compositions show higher conductivity. The Co/Fe ratio does not influence much the p-type semi-conduction. Iron-rich compositions revealed more metal-like conduction behavior. The degree of overlap between transition metal d-orbitals and oxygen p-orbitals depends on the Ba/Sr as well as on the Co/Fe ratios.

引用

页码：277 / 284

页数：8

共 39 条

[1] Local Charge Disproportion in a High-Performance Perovskite [J].