TY - JOUR
T1 - Oxygen nonstoichiometry and defect equilibrium in La2 - xSrxNiO4 + δ
AU - Nakamura, Takashi
AU - Yashiro, Keiji
AU - Sato, Kazuhisa
AU - Mizusaki, Junichiro
N1 - Funding Information:
This research was partly supported by the Grant-in-Aid for Scientific Research on Priority Area, “Nanoionics (439)” and the Grant-in-Aid for JSPS Fellowship by Ministry of Education, Science, and Culture, Sports and Technology.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009/4/27
Y1 - 2009/4/27
N2 - Nonstoichiometric variation of oxygen content in La2 - xSrxNiO4 + δ (x = 0, 0.1, 0.2, 0.3, 0.4) and decomposition P(O2) were determined by means of high temperature gravimetry and coulometric titration. The measurements were carried out in the temperature range between 873 and 1173 K and the P(O2) range between 10- 20 and 1 bar. La2 - xSrxNiO4 + δ showed the oxygen excess and the oxygen deficient compositions depending on P(O2), temperature, and the Sr content. The value of partial molar enthalpy of oxygen approaches zero as δ increases in the oxygen excess region, which indicate that the interstitial oxygen formation reaction is suppressed as δ increase. The relationship between δ and logP(O2) were analyzed by two types of defect equilibrium models. One is a localized electron model, and the other is a delocalized electron model. Both models can well explain the oxygen nonstoichiometry of La2 - xSrxNiO4 + δ with a regular solution approximation.
AB - Nonstoichiometric variation of oxygen content in La2 - xSrxNiO4 + δ (x = 0, 0.1, 0.2, 0.3, 0.4) and decomposition P(O2) were determined by means of high temperature gravimetry and coulometric titration. The measurements were carried out in the temperature range between 873 and 1173 K and the P(O2) range between 10- 20 and 1 bar. La2 - xSrxNiO4 + δ showed the oxygen excess and the oxygen deficient compositions depending on P(O2), temperature, and the Sr content. The value of partial molar enthalpy of oxygen approaches zero as δ increases in the oxygen excess region, which indicate that the interstitial oxygen formation reaction is suppressed as δ increase. The relationship between δ and logP(O2) were analyzed by two types of defect equilibrium models. One is a localized electron model, and the other is a delocalized electron model. Both models can well explain the oxygen nonstoichiometry of La2 - xSrxNiO4 + δ with a regular solution approximation.
KW - KNiF type oxides
KW - LaNiO
KW - Lanthanum nickelate
KW - Layered perovskite
KW - Oxygen nonstoichiometry
UR - http://www.scopus.com/inward/record.url?scp=63449099762&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=63449099762&partnerID=8YFLogxK
U2 - 10.1016/j.ssi.2009.01.013
DO - 10.1016/j.ssi.2009.01.013
M3 - Article
AN - SCOPUS:63449099762
VL - 180
SP - 368
EP - 376
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
IS - 4-5
ER -