Impact of the Volatile Cr-species' Attack on the Conductivity of La(Ni,Fe)O3

This study demonstrates the detrimental impact of Cr on the electronic conductivity of a $LaNi_{0.6}Fe_{0.4}O_3$ (LNF) porous cathode layer at 800 ºC. Vapor transport of Cr-species, originating from a porous metallic foam, and subsequent reaction with LNF results in a decrease of the electronic conductivity of the LNF-layer. Cr has been detected throughout the whole cross-section of the LNF-layer. Transmission electron microscopy revealed that Cr is gradually incorporated into the LNF-grains, while Ni is proportionally expelled. The progressing Cr deposition and penetration into the LNF-grains most likely explains the electronic conductivity drop. The Cr-poisoning impact on the electronic conductivity of the LNF porous layer is considerably smaller at 600ºC than at 800ºC. A tentative mechanism for the Cr attack and its influence on the electronic conductivity of the LNF layer will be presented.