Phase relations in the system Sr-Cr-O and thermodynamic properties of SrCrO4 and Sr3Cr2O8

Thermodynamic modeling of La2O3–SrO–Mn2O3–Cr2O3for solid oxide fuel cell applications

“…We propose the model (La 31 3 for the complex perovskite phase. Optimized by experiments in pseudoternary and pseudoquaternary oxide subsystems, this model allows the quantitative calculation of defects as a function of composition, temperature, and oxygen partial pressure.…”

“…34 Differences concern the reported stabilities of further compounds 31,32,[35][36][37][38][39] : for the stabilities of SrCr 2 O 4 and Sr 2 CrO 4 , we trust the accurate study of Jacob and Abraham. 31 On the other hand, the conflicting phase equilibria presented by Kisil et al 35 lack experimental details. Sr 3 Cr 2 O 7 32 was approved as high-pressure phase only.…”

“…16 Previous assessments of the La-O, Cr-O, La-Cr-O, and Cr-Mn-O oxide databases are adopted from Povoden et al, [17][18][19][20][21] with some modifications denoted in the supplement file to this paper, LSCM_v1.0.tcm (ThermoCalc macrofile), and the La-Sr-Mn-O oxide database is taken from Grundy et al, [22][23][24][25][26][27] also with the following slight modification: Grundy et al 23,24 allowed Mn 31 on the A-site of LSM to reproduce experimental oxygen nonstoichiometries under low oxygen partial pressures. Due to large differences between the ionic radii of La 31 and Mn 31 and possible coordination numbers (1.5 Å for 12-fold coordinated La 31 , 0.785 Å for at maximum 6-fold coordinated Mn 31 ), 28 we omit Mn 31 on the A-site. With this manipulation of the original model, still the results of calculated oxygen nonstoichiometry of LSM perovskite in equilibrium with MnO compare well with experimental data.…”

“…27 A. Sr-Cr-oxide Thermodynamic functions for Sr-Cr-oxides in the Scientific Group Thermodata Europe Substances Database (SSUB) 29 are based on estimates. 30 We propose optimized thermodynamic functions for oxide phases of the Sr-Cr-O oxide system resulting from the assessment of all available experimental data: agreement exists between Gibbs energies of formation of SrCrO 4 determined by emf technique using a Y 2 O 3 -stabilized ZrO 2 electrolyte, 31,32 whereas emf measurements using CaF 2 -based emf technique 33 led to conflicting results likely caused by competing reactions. 34 Differences concern the reported stabilities of further compounds 31,32,[35][36][37][38][39] : for the stabilities of SrCr 2 O 4 and Sr 2 CrO 4 , we trust the accurate study of Jacob and Abraham.…”

“…3, showing 37 by manipulating the model parameters of solid oxides, will lead to a worse reproduction of both the newer thermodynamic and phase diagram data. 31,32 On the other hand, the chosen liquid description allows at least for qualitative reproduction of experimental phase equilibria.…”