TY  - JOUR
AU  - Tietz, F.
AU  - Arul Raj, I.
AU  - Ma, Q.
AU  - Baumann, S.
AU  - Mahmoud, A.
AU  - Hermann, Raphael
TI  - Material properties of perovskites in the quasi-ternary system LaFeO$_{3}$–LaCoO$_{3}$–LaNiO$_{3}
JO  - Journal of solid state chemistry
VL  - 237
SN  - 0022-4596
CY  - Orlando, Fla.
PB  - Academic Press
M1  - FZJ-2016-01979
SP  - 183 - 191
PY  - 2016
AB  - An overview is presented on the variation of electrical conductivity, oxygen permeation, and thermal expansion coefficient as a function of the composition of perovskites in the quasi-ternary system LaFeO3–LaCoO3–LaNiO3. Powders of thirteen nominal perovskite compositions were synthesized under identical conditions by the Pechini method. The powder X-ray diffraction data of two series, namely La(Ni0.5Fe0.5)1−xCoxO3 and LaNi0.5-xFexCo0.5O3, are presented after the powders had been sintered at 1100 °C for 6 h in air. The measurements revealed a rhombohedral structure for all compositions except LaNi0.5Fe0.5O3 for which 60% rhombohedral and 40% orthorhombic phase was found. The maximum DC electrical conductivity value of the perovskites at 800 °C was 1229 S cm−1 for the composition LaCoO3 and the minimum was 91 S cm−1 for the composition LaCo0.5Fe0.5O3. The oxygen permeation of samples with promising conductivities at 800 °C was one order of magnitude lower than that of La0.6Sr0.4Co0.8Fe0.2O3 (LSCF). The highest value of 0.017 ml cm−2 min−1 at 950 °C was obtained with LaNi0.5Co0.5O3. The coefficients of thermal expansion varied in the range of 13.2×10−6 K−1 and 21.9×10−6 K−1 for LaNi0.5Fe0.5O3 and LaCoO3, respectively. 57Fe Mössbauer spectroscopy was used as probe for the oxidation states, local environment and magnetic properties of iron ions as a function of chemical composition. The substitution had a great influence on the chemical properties of the materials.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000373661100026
DO  - DOI:10.1016/j.jssc.2016.01.024
UR  - https://juser.fz-juelich.de/record/283682
ER  -