Chemical stability of Ca3Co4−xO9+δ/CaMnO3−δ p–n junction for oxide-based thermoelectric generators
| Autor: | Mari-Ann Einarsrud, Thomas Aarflot Storaas, Temesgen Debelo Desissa, Kjell Wiik, Anette Eleonora Gunnæs, Truls Norby, Clas Persson, Matthias Schrade, Sandeep Gorantla, Kristian Berland, Nikola Kanas, Raluca Tofan |
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| Rok vydání: | 2020 |
| Předmět: |
Diffraction
Materials science General Chemical Engineering Oxide Analytical chemistry 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology oxide-based thermoelectric generators 01 natural sciences 0104 chemical sciences low electrical resistance chemistry.chemical_compound Thermoelectric generator chemistry Electrical resistance and conductance Transmission electron microscopy transmission electron microscopy Density functional theory Chemical stability 0210 nano-technology p–n junction |
| Zdroj: | RSC Advances |
| ISSN: | 2046-2069 |
| Popis: | An all-oxide thermoelectric generator for high-temperature operation depends on a low electrical resistance of the direct p–n junction. Ca3Co4−xO9+δ and CaMnO3−δ exhibit p-type and n-type electronic conductivity, respectively, and the interface between these compounds is the material system investigated here. The effect of heat treatment (at 900 °C for 10 h in air) on the phase and element distribution within this p–n junction was characterized using advanced transmission electron microscopy combined with X-ray diffraction. The heat treatment resulted in counter diffusion of Ca, Mn and Co cations across the junction, and subsequent formation of a Ca3Co1+yMn1−yO6 interlayer, in addition to precipitation of Co-oxide, and accompanying diffusion and redistribution of Ca across the junction. The Co/Mn ratio in Ca3Co1+yMn1−yO6 varies and is close to 1 (y = 0) at the Ca3Co1+yMn1−yO6–CaMnO3−δ boundary. The existence of a wide homogeneity range of 0 ≤ y ≤ 1 for Ca3Co1+yMn1−yO6 is corroborated with density functional theory (DFT) calculations showing a small negative mixing energy in the whole range. Open Access Article. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. |
| Databáze: | OpenAIRE |
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