Grain boundary Fe-doping effects in LSGM

resumo

The electrical properties of La(0.95)Sr(0.05)Cia(0.90)Mg(0.10)O(3-delta) (LSGM) were modified by selective doping of the grain boundaries, using LaFeO3 screen-printed layers and annealing at high temperature to promote Fe diffusion into LSGM. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses showed that iron was mainly located along the grain boundaries with the bulk grain composition almost unchanged. Impedance spectra showed a significant increase in the total conductivity for the Fe-doped samples, the effect being greater for the grain boundary contribution. The formation of a parallel pathway for electronic conduction along the grain boundaries explains these effects. Ageing of these samples at high temperature, after removal of the Fe source, showed a steady shift to the original LSGM behaviour, due to dilution of Fe throughout the samples. (C) 2008 Elsevier B.V. All rights reserved.

palavras-chave

ELECTRONIC CONDUCTIVITY; MIXED CONDUCTION; PERMEABILITY; OXIDES

categoria

Chemistry; Physics

autores

Gomes, E; Figueiredo, FM; Marques, FMB

nossos autores

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".