Structural peculiarities in the β phase of the La0.75Ce0.25Ni4.8Al0.2 deuterides
| Autor: | Dirk Wallacher, J. Czub, W. Jamka, Łukasz Gondek, A. Zarzecka, Nico Grimm, Andreas Hoser, Janusz Przewoźnik |
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| Rok vydání: | 2019 |
| Předmět: |
Valence (chemistry)
Materials science Mechanical Engineering Neutron diffraction Alloy Metals and Alloys chemistry.chemical_element Sorption 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Crystallography Cerium Deuterium chemistry Mechanics of Materials Desorption Materials Chemistry engineering 0210 nano-technology Solid solution |
| Zdroj: | Journal of Alloys and Compounds. 788:533-540 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2019.02.259 |
| Popis: | In this contribution the structural, magnetic and sorption properties of the novel La0.75Ce0.25Ni4.8Al0.2 alloy and its deuterides are discussed. The collected data indicate good stability of the alloy during the cycle-life and thermal treatment tests. Particularly, the desorption pressure is almost constant versus the cycle number. The results of the in-situ neutron diffraction studies show the unusual behaviour of the deuterium rich β phase. Unexpectedly, the β phase belongs to the same P6/mmm space group as the hydrogen poor α phase. Moreover, the β phase behaves like a solid solution on the plateau of the pressure-composition-temperature (PCT) curve. The deuterium sites and their occupations in both α and β phases are determined from the neutron diffraction data, giving the first-hand insight into the mechanism of the PCT hysteresis. As far as the magnetic properties are concerned, cerium is trivalent in the investigated alloy. However, no magnetic ordering down to 3 K is observed. It can be concluded that the sorption properties of the crystal depend on the cerium valence, what distinguishes the alloy from the other compositions. |
| Databáze: | OpenAIRE |
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