Thermodynamic study of the sodium chromite NaCrO2
| Autor: | David Bonina, Jean-Louis Flèche, S. Chatain, Nicolas David, J. L. Courouau, Marion Rouhard, Christophe Bonnet |
|---|---|
| Přispěvatelé: | Service de la Corrosion et du Comportement des Matériaux dans leur Environnement (SCCME), Département de Physico-Chimie (DPC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay |
| Rok vydání: | 2021 |
| Předmět: |
Phase transition
Materials science Mechanical Engineering Metals and Alloys Thermodynamics [CHIM.MATE]Chemical Sciences/Material chemistry 02 engineering and technology Atmospheric temperature range 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Heat capacity 0104 chemical sciences Gibbs free energy symbols.namesake Differential scanning calorimetry Mechanics of Materials Ab initio quantum chemistry methods Differential thermal analysis Phase (matter) Materials Chemistry symbols 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds Journal of Alloys and Compounds, 2021, 882, pp.160784. ⟨10.1016/j.jallcom.2021.160784⟩ |
| ISSN: | 0925-8388 |
| Popis: | A thermodynamic study was undertaken on two kinds of NaCrO2(s) powder, a commercial and an experimental one synthetized. Heat capacity measurements were carried out in the temperature range of 25–600 °C using a differential scanning calorimeter. Gibbs energy of formation versus temperature was deduced using these experimental data, the enthalpy of formation from literature and the entropy at room temperature deduced from ab initio calculations combining with a quasi-harmonic statistical model. The equation obtained is given by: ΔfG°(T) (NaCrO2) (kJ/mol O2)=−876.094+0.191xT (±2%). The temperature of phase transition measured by differential thermal analysis at (819 ± 4) °C is slightly higher than the temperature in the literature attributed to the decomposition of NaCrO2 into Cr2O3 and Na2O. However, the X-ray diffraction patterns showed only NaCrO2 phase which didn’t confirm the decomposition reaction. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect