Microstructures and Thermoelectric Properties of NaCo2O4 Prepared by Double-step Sintering
| Autor: | Eishi Maeda, Michitaka Ohtaki |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Materials science
Mechanical Engineering Metallurgy Metals and Alloys Oxide Sintering Thermoelectric materials Microstructure Industrial and Manufacturing Engineering law.invention chemistry.chemical_compound chemistry law Seebeck coefficient Thermoelectric effect Materials Chemistry Calcination Crystallite |
| Zdroj: | Journal of the Japan Society of Powder and Powder Metallurgy. 47:1159-1164 |
| ISSN: | 1880-9014 0532-8799 |
| DOI: | 10.2497/jjspm.47.1159 |
| Popis: | The thermoelectric properties of sintered bodies of NaCo2O4, which is so far the most promising p-type candidate for oxide thermoelectric material, are investigated in terms of their sintering conditions. Double-step sintering, for which single-phase NaCo2O4 obtained by calcination and sintering with addition of 10% excess of Na each time is re-ground and sintered again, is revealed to attain a marked improvement in the thermoelectric performance of the oxide. The improvement is due to increase in both Seebeck coefficient and electrical conductivity, and is attributed to a distinct enhancement of the two-dimensionality in the crystallites constituting the sintered body. The oxide sintered body consequently attains the figure-of-merit of 0.88×10-3K-1 at 600°C, and the maximum ZT of 0.78 at 800°C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|