TY - JOUR
T1 - Energetics of lanthanide cobalt perovskites
T2 - LnCoO3-δ (Ln = La, Nd, Sm, Gd)
AU - Sahu, Sulata Kumari
AU - Tanasescu, Speranta
AU - Scherrer, Barbara
AU - Marinescu, Cornelia
AU - Navrotsky, Alexandra
N1 - Publisher Copyright:
© The Royal Society of Chemistry 2015.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/8/20
Y1 - 2015/8/20
N2 - Lanthanide cobalt perovskites LnCoO3-δ (Ln = La, Nd, Sm, and Gd) are important materials for electroceramics, catalysts, and electrodes in solid oxide fuel cells. Formation enthalpies of LnCoO3-δ compounds were measured using high temperature oxide melt solution calorimetry. The formation enthalpies of LaCoO2.992, NdCoO2.985, SmCoO2.982 and GdCoO2.968 from constituent binary oxides (Ln2O3, CoO) and O2 gas are -111.87 ± 1.36, -98.49 ± 1.33, -91.56 ± 1.46 and -88.16 ± 1.45 kJ mol-1, respectively. Thus these perovskites become energetically less stable with decrease in ionic radius of the lanthanide (from La to Gd), which corresponds to a decreasing tolerance factor and increasing oxygen deficiency. The thermodynamic stability of LaCoO2.992, NdCoO2.985, SmCoO2.982 and GdCoO2.968 was also assessed considering their oxygen partial pressures for decomposition, with good agreement between thermochemical and equilibrium data.
AB - Lanthanide cobalt perovskites LnCoO3-δ (Ln = La, Nd, Sm, and Gd) are important materials for electroceramics, catalysts, and electrodes in solid oxide fuel cells. Formation enthalpies of LnCoO3-δ compounds were measured using high temperature oxide melt solution calorimetry. The formation enthalpies of LaCoO2.992, NdCoO2.985, SmCoO2.982 and GdCoO2.968 from constituent binary oxides (Ln2O3, CoO) and O2 gas are -111.87 ± 1.36, -98.49 ± 1.33, -91.56 ± 1.46 and -88.16 ± 1.45 kJ mol-1, respectively. Thus these perovskites become energetically less stable with decrease in ionic radius of the lanthanide (from La to Gd), which corresponds to a decreasing tolerance factor and increasing oxygen deficiency. The thermodynamic stability of LaCoO2.992, NdCoO2.985, SmCoO2.982 and GdCoO2.968 was also assessed considering their oxygen partial pressures for decomposition, with good agreement between thermochemical and equilibrium data.
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U2 - 10.1039/c5ta03655k
DO - 10.1039/c5ta03655k
M3 - Article
AN - SCOPUS:84942280064
SN - 2050-7488
VL - 3
SP - 19490
EP - 19496
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 38
ER -