Cation diffusion in (La,Ca)CrO3 perovskite by SIMS

被引：38

作者：

Horita, T ^{[1
]}

Ishikawa, M ^{[1
]}

Yamaji, K ^{[1
]}

Sakai, N ^{[1
]}

Yokokawa, H ^{[1
]}

Dokiya, M ^{[1
]}

机构：

[1] Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 305, Japan

来源：

SOLID STATE IONICS | 1998年 / 108卷 / 1-4期

关键词：

(La; Ca)CrO(3); perovskite; cation diffusion; SOFC; SIMS;

D O I：

10.1016/S0167-2738(98)00067-8

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：

Cation diffusion in (La,Ca)CrO(3) was examined by two kinds of diffusion experiments: Sr(NO(3))(2) solution applied experiment on the La(0.75)Ca(0.25)CrO(3) surface and a diffusion couple experiment of La(0.95)Sr(0.05)CrO(3) /La(0.75)Ca(0.25)CrO(3), with secondary ion mass spectrometry (SIMS) analysis. The obtained bulk chemical interdiffusion coefficients for Ca-Sr from the two different experiments were almost on the same line in the temperature dependence plots, as follows: D(bulk) (cm(2)s(-1)) = 2.66 x 10(-2).exp(- 318(kJ mol(-1))/RT) (1173-1673 K). The grain boundary chemical interdiffusion coefficients for Ca-Sr were obtained by the SIMS depth profiles with a new fitting equation, as follows: D(gb) (sm(2)s(-1)) = 10.1.exp (- 261 (kJ mol(-1))/RT) (1173-1373 K). For the calculation of the grain boundary diffusion coefficient, the width of the grain boundary is assumed to be 1 nm. The diffusion coefficient for grain boundary interdiffusion of Ca-Sr is calculated to be five times higher than that for bulk diffusion at the same temperature. The grain boundary diffusion coefficient increased with the 0.66 power of p(O(2)), which has a relationship with the valence change of Cr at the grain boundary. (C) 1998 Elsevier Science B.V. All rights reserved.

引用

页码：383 / 390

页数：8

共 9 条

[1]

Akashi T, 1997, ELEC SOC S, V97, P1263

[2] An improved method, based on Whipple's exact solution, for obtaining accurate grain-boundary diffusion coefficients from shallow solute concentration gradients [J].