Book/Report

FZJ-2019-01521

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Untersuchungen zur Verdampfung und Thermodynamik von Perowskiten auf der Basis von LaCrO$_{3}$ für Hochtemperatur-Brennstoffzellen mit Festelektrolyt (SOFC)

Peck, D. H. (Corresponding author)FZJ* ; Hilpert, K.FZJ* ; Miller, M. ; Kobertz, D.FZJ* ; Nickel, H.FZJ*

1996
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/21693

Report No.: Juel-3253

Abstract: LaCrO$_{3}$ based perovskites are generally used as material for the ceramic interconnect of solid oxide fuel cells (SOFC). The stability of the used interconnect materials has to be guaranteed under oxidizing and reducing condition as well as for operating temperatures up to 1000 °C in order to render possible operation time periods of more than 40.000 h. Knowledge on the vaporization, the thermochemical data, and the phase diagrams belonging to the used perovskites is, therefore, necessary. This knowledge is also necessary for the development of welldefined production processes. Vaporization studies by Knudsen effusion mass spectrometry and phase diagram studies were carried out for the determination of the missing data. Reliable data for the Gibbs energy and entropy of formation were determined for LaCrO$_{3}$ for the first time. Contributions to the SrO-Cr$_{2}$O$_{3}$-La$_{2}$O$_{3}$ and CaO-Cr$_{2}$O$_{3}$-La$_{2}$O$_{3}$ phase diagrams were experimentally determined. Thermodynamic activities resulted for the oxide components at 2000 K in the phases La$_{1-x}$Sr$_{x}$CrO$_{3-8}$, La$_{1-x}$Ca$_{x}$CrO$_{3-8}$, La$_{0.8}$Sr$_{0.2-x}$Ca$_{x}$CrO$_{3-8}$ and LaCr$_{1-x}$Mg$_{x}$O$_{3-8}$. Gibbs free energies of formation were determined for the first and last mentioned phases as well as for the Ruddlesden-Popper phases (La$_{3}$A)Cr$_{3}$O$_{10}$, (La$_{2}$A)Cr$_{2}$O$_{7}$ and (LaA)CrO$_{4}$ (A = Sr or Ca) as well as for the spinel phase MgCr$_{2}$O$_{4}$. Finally, thermochemical computations were carried out in order to determine the chromium vaporization from the metallic interconnect (Cr containing alloy protected from corrosion by a Cr$_{2}$O$_{3}$ scale) and from the ceramic interconnect (LaCrO$_{3}$ and La$_{0.84}$Sr$_{0.16}$CrO$_{3-8}$).

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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