The NaF-AlF3-Al2O3-Na2O system—I standard free energy of formation of α-aluminium oxide from emf measurements
✍ Scribed by Å. Sterten; S. Haugen; K. Hamberg
- Publisher
- Elsevier Science
- Year
- 1976
- Tongue
- English
- Weight
- 375 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
The behaviour of oxygen and alummium electrodes was studied by means of emf measurements in Na,AlF, melts saturated with oc-AlzO, in the temperature range 1233-1310K.
The results indicate that the electrodes are reversible when they are separated by an a-Al,O, diaphragm. However, the alumimum electrode reacts with the melt to a certain extent. This means that the standard free energy data for a-Al,O, are not easily derived from emJ measurements in Na3AlF, melts saturated with a-Al,O,.
However, the emf for the following cell (J't)O~ILi~AlF~,,,, AIF,,,,. AlZ03,..,//Li~Al~~,,, ,. AIF, ,,,. Al103,,,/Al was in excellenr aereement with values derived from standard free energy data for z-Al,O, formation in the JANAF TaYbles in the range 102(X1275 K.