Defect structure and thermochemistry of YBaCo2O6-δ
| Autor: | Dmitry S. Tsvetkov, A. Yu. Zuev, R.E. Yagovitin, Vladimir V. Sereda, Antoine Maignan, Anton L. Sednev-Lugovets |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Enthalpy Analytical chemistry chemistry.chemical_element 02 engineering and technology Calorimetry Atmospheric temperature range 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Oxygen Endothermic process Standard enthalpy of formation 010406 physical chemistry 0104 chemical sciences Cobaltite chemistry.chemical_compound chemistry Thermochemistry Physical and Theoretical Chemistry 0210 nano-technology Instrumentation |
| Zdroj: | Thermochimica Acta. 698:178886 |
| ISSN: | 0040-6031 |
| DOI: | 10.1016/j.tca.2021.178886 |
| Popis: | The defect structure analysis of the oxygen deficient YBaCo2O6-δ double perovskite cobaltite confirms that the model proposed earlier for RBaCo2O6-δ (R – Pr, Gd, La) holds also for YBaCo2O6-δ. In particular, a good agreement between the pO2(T, δ) model function and experimental pO2 – T – δ data is obtained for this oxide. By means of high-temperature drop calorimetry, the enthalpy increments of YBaCo2O6-δ samples with different initial oxygen contents (0.67 ≤ δ ≤ 1) were measured in air in the (1123–1273) K temperature range. The results obtained for YBaCo2O5.0 were fitted using a Maier-Kelley function. The smoothed values of Δ 298.15 T H ∘ , Cp(T), and Δ 298.15 T S ∘ were calculated for thermodynamically stable YBaCo2O5.0 in the temperature range 1150 ≤ T, K ≤ 1350. The drop calorimetric results for the metastable YBaCo2O5.33 were used to evaluate the standard enthalpy of its reduction at 298.15 K, Δ H r e d ∘ , as (161 ± 15) kJ·(mol O2)-1 (expanded uncertainty with ≈0.95 level of confidence), which is significantly less endothermic than Δ H r e d ∘ of some other double perovskite cobaltites, RBaCo2O6-δ (R – Pr, Gd), within similar oxygen nonstoichiometry ranges (0.5 ≤ δ ≤ 1.0). |
| Databáze: | OpenAIRE |
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