TY  - JOUR
AU  - Heuer, Sabrina A.
AU  - Schierholz, Roland
AU  - Alekseev, Evgeny
AU  - Peters, Lars
AU  - Mueller, David N.
AU  - Duchoň, Tomáš
AU  - Vibhu, Vaibhav
AU  - Tempel, Hermann
AU  - de Haart, L.G.J.
AU  - Kungl, Hans
AU  - Eichel, Rüdiger-A.
TI  - Oxygen Nonstoichiometry and Valence State of Manganese in La 1– x Ca x MnO 3+δ
JO  - ACS omega
VL  - 6
IS  - 14
SN  - 2470-1343
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2021-01404
SP  - 9638 - 9652
PY  - 2021
AB  - Perovskites of the ABO3 type, such as LaMnO3, can be used as air electrodes in solid oxide fuel cells and electrolyzers. Their properties can be tuned by A- and B-site substitutions. The influence of La substitution by Ca on the oxygen nonstoichiometry has been investigated frequently, but the results depend highly on the synthesis and atmospheric conditions. In this work, a series of La1–xCaxMnO3+δ (x = 0–0.5) was synthesized using conventional solid-state synthesis under an air atmosphere. The structures of the materials were studied in detail with powder X-ray diffraction. The initial oxygen nonstoichiometries were determined using thermogravimetric reduction. The samples were subsequently analyzed in terms of defect chemistry in dependence of temperature, atmosphere, and Ca content via thermogravimetric analysis. The changes in the manganese charge states were investigated by X-ray absorption near-edge spectroscopy experiments. The influence of intrinsic and extrinsic effects on the Mn-valence state of the differently Ca-substituted samples as calculated from thermogravimetric analysis and as determined directly from X-ray absorption near-edge spectroscopy is presented.
LB  - PUB:(DE-HGF)16
C6  - 33869944
UR  - <Go to ISI:>//WOS:000640649500033
DO  - DOI:10.1021/acsomega.1c00208
UR  - https://juser.fz-juelich.de/record/891166
ER  -