TY - JOUR
T1 - Oxygen nonstoichiometry and electrical conductivity of LaNi0.6Fe0.4O3-δ at high temperatures under various oxygen partial pressures
AU - Niwa, Eiki
AU - Uematsu, Chie
AU - Mizusaki, Junichiro
AU - Hashimoto, Takuya
N1 - Funding Information:
This study was financially supported by grants from the “Strategic Research Base Development” Program for Private Universities ( S0901022 ) subsidized by MEXT (2009) and from Nihon University Strategic Projects for Academic Research “Nanotechnology Excellence-Nanomaterial based Photonic and Quantum Technologies”. This work was performed under the Cooperative Research Program of “Network Joint Research Center for Materials and Devices”.
Publisher Copyright:
© 2015 Elsevier B.V.All rights reserved.
PY - 2015/6
Y1 - 2015/6
N2 - Temperature and oxygen partial pressure, P(O2), dependence of oxygen nonstoichiometry of LaNi0.6Fe0.4O3 - δ, which is a new candidate cathode material for solid oxide fuel cells, has been determined by the equilibrium thermogravimetry. The P(O2) and temperature dependence of the electrical conductivity of LaNi0.6Fe0.4O3 - δ has also been measured. It has been clarified that the oxygen content, 3 - δ of LaNi0.6Fe0.4O3 - δ at temperatures between 300°C and 700°C under 10-4 bar ≤ P(O2) ≤ 1 bar is around 2.90, which can be explained by Ni and Fe valence of + 2 and + 4, respectively. Temperature and P(O2) dependence of the oxygen nonstoichiometry and the electrical conductivity is small for LaNi0.6Fe0.4O3 - δ, which can be ascribed to small variation of the average valence of B-site ion by temperature and P(O2) due to occurrence of charge compensation between Ni ion and Fe ion. The easy occurrence of the charge compensation corresponds to hopping conduction with small, temperature and P(O2) independent activation energy. By combination of oxygen nonstoichiometry and electrical conductivity, it has been clarified that LaNi0.6Fe0.4O3 - δ is p-type conductor with mobility of 0.257 cm2 V- 1 s- 1, which is independent on temperature and P(O2). Hole concentration at temperatures between 300°C and 800°C under - 4 ≤ log(P(O2) ≤ 0 is 3-4 × 1021 cm- 3.
AB - Temperature and oxygen partial pressure, P(O2), dependence of oxygen nonstoichiometry of LaNi0.6Fe0.4O3 - δ, which is a new candidate cathode material for solid oxide fuel cells, has been determined by the equilibrium thermogravimetry. The P(O2) and temperature dependence of the electrical conductivity of LaNi0.6Fe0.4O3 - δ has also been measured. It has been clarified that the oxygen content, 3 - δ of LaNi0.6Fe0.4O3 - δ at temperatures between 300°C and 700°C under 10-4 bar ≤ P(O2) ≤ 1 bar is around 2.90, which can be explained by Ni and Fe valence of + 2 and + 4, respectively. Temperature and P(O2) dependence of the oxygen nonstoichiometry and the electrical conductivity is small for LaNi0.6Fe0.4O3 - δ, which can be ascribed to small variation of the average valence of B-site ion by temperature and P(O2) due to occurrence of charge compensation between Ni ion and Fe ion. The easy occurrence of the charge compensation corresponds to hopping conduction with small, temperature and P(O2) independent activation energy. By combination of oxygen nonstoichiometry and electrical conductivity, it has been clarified that LaNi0.6Fe0.4O3 - δ is p-type conductor with mobility of 0.257 cm2 V- 1 s- 1, which is independent on temperature and P(O2). Hole concentration at temperatures between 300°C and 800°C under - 4 ≤ log(P(O2) ≤ 0 is 3-4 × 1021 cm- 3.
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U2 - 10.1016/j.ssi.2015.02.022
DO - 10.1016/j.ssi.2015.02.022
M3 - Article
AN - SCOPUS:84925660916
SN - 0167-2738
VL - 274
SP - 119
EP - 122
JO - Solid State Ionics
JF - Solid State Ionics
ER -