Enthalpies of formation of RCoO3-δ (R = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y) perovskite cobaltites

被引：1

作者：

Sereda, Vladimir V. ^{[1
]}

Tsvetkov, Dmitry S. ^{[1
]}

Sereda, Anna, V ^{[1
]}

Yagovitin, Roman E. ^{[1
]}

Mazurin, Maxim O. ^{[1
]}

Malyshkin, Dmitry A. ^{[1
]}

Ivanov, Ivan L. ^{[1
]}

Zuev, Andrey Yu. ^{[1
]}

机构：

[1] Ural Fed Univ, Inst Nat Sci & Math, 19 Mira St, Ekaterinburg 620002, Russia

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2024年 / 1003卷

基金：

俄罗斯科学基金会;

关键词：

Rare earth alloys and compounds; Oxide materials; Thermodynamic properties; Thermochemistry; Calorimetry; Thermal analysis; STANDARD GIBBS ENERGY; EFFECTIVE IONIC-RADII; CO-O; THERMODYNAMIC PROPERTIES; DEFECT STRUCTURE; LN(2)O(3)-CO-CO2O3 SYSTEM; THERMAL-PROPERTIES; PHASE-EQUILIBRIA; SPIN TRANSITION; CHARGE-TRANSFER;

D O I：

10.1016/j.jallcom.2024.175645

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Standard enthalpies of formation at 298.15 K, Delta fH degrees 298.15, for RCoO3-delta (R = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y) perovskite-type rare-earth cobaltites were obtained from the combined results of drop and reduction calorimetry. The relationship between the oxygen nonstoichiometry, delta, and thermodynamics of RCoO3-delta was discussed. The fact that RCoO3-delta with smaller ionic radius of R3+ tend to be less stable, having more positive enthalpy of formation from binary oxides (CoO and R2O3), Delta f,oxH degrees 298.15, was confirmed for all the studied RCoO3-delta. Drop calorimetry results were also used in discussing, comparing and assessing the literature heat capacity, Cp(T), data for RCoO3-delta (R /= Y). For YCoO3-delta, both Delta fH degrees 298.15 and Cp(T) were obtained for the first time solely from the drop calorimetric results; Delta fH degrees 298.15 values determined by two different methods perfectly agree with each other. The reference data and Cp(T) of RCoO3-delta were used to calculate Delta fH degrees 298.15 from the published EMF measurement results so as to compare the available Delta f,oxH degrees 298.15(RCoO3-delta) values. An unusual dependence of Delta fH degrees 298.15(LaCoO3-delta) on its heat treatment history was identified and supported by the additional isoperibolic solution calorimetry measurements.

引用

页数：11