Influence of synthesis route on morphology and electrical properties of LaNi0.6Fe0.4O3

Cr-tolerance of the IT-SOFC La(Ni,Fe)03 material

“…There is a significant difference in the slope of the linear trend between the reference sample and the Cr-exposed sample, hence the effective activation energy increased significantly for the Cr-exposed layer from 0.06 eV to 0.26 eV. The activation energy measured for the Cr-free reference porous LNF layer is similar to literature data of LNF (0.05−0.08 eV) [51,52], whereas the E a value of the Cr-exposed layer is comparable to La(Fe,Cr)O 3 compounds (0.20−0.30 eV) [42,[53][54][55]. …”

“…3.5 shows the relation between log(σT) versus the inverse absolute temperature. This relationship was chosen because literature indicates that the electronic conductivity of LaNi x Fe 1−x O 3 series (x 0.6) can be described by the thermally activated small polaron mechanism [32,51] which is generally expressed as:…”

“…The Cr-substituted LNF phase, formed in the outer shell of the LNF particles and necks during Cr-exposure (as schematically shown in Fig. 3.12), has a significantly lower electronic conductivity [42,53] compared to a Ni-rich LNF phase [32,51]. As a consequence the Cr-intrusion results in a lower volume of a well conducting LNF-phase causing a decrease in the overall in-plane conductivity of the porous LNF-layer.…”

Sintering temperature dependence of conductivity, porosity and specific surface area of LaNi0.6Fe0.4O3 ceramics as cathode material for solid oxide fuel cells—Superiority of Pechini method among various solution mixing processes

“…At such a high temperature, only a small specific surface area might be obtained owing to too much sintering and the abnormal growth of LaNi 0.6 Fe 0.4 O 3 grains, resulting in small probability of O 2 gas ionization to O 2À at the interface between the cathode and gas phase. Since it was reported that an appropriate density for a cathode material is approximately 70% [3], the sintering temperature of cathode materials should be reduced.…”

“…So far, various solution mixing methods such as Pechini method [4], glycine-nitrate process (GN process), a gel-citrate complexation route (GC complexation), a coprecipitation route (CP route) [3], and combustion synthesis routes using citric-gel (CG combustion) or urea (urea combustion) [5] have been proposed as preparation methods of LaNi 0. 6 The sintering temperature dependence of the porosity, specific surface area and electrical conductivity of LaNi 0.6 Fe 0.4 O 3 , which is one of the candidate materials for solid oxide fuel cells (SOFC) cathodes, prepared by Pechini method has been investigated.…”