Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system
The NaH + Al + 0.02CeCl3 system has been studied by high-resolution X-ray synchrotron diffraction and transmission electron microscopy (TEM), after planetary milling under hydrogen and hydrogen (H) cycling. Isothermal absorption kinetics were determined at 150 °C, and compared with the NaH + Al + 0....
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
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Elsevier Ltd
2011
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| Online Access: | http://hdl.handle.net/20.500.11937/17306 |
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| author | Pitt, Mark Paskevicius, Mark Webb, C. Sorby, M. Delleda, S. Jensen, T. Hauback, B. Buckley, Craig Gray, E. |
| author_facet | Pitt, Mark Paskevicius, Mark Webb, C. Sorby, M. Delleda, S. Jensen, T. Hauback, B. Buckley, Craig Gray, E. |
| author_sort | Pitt, Mark |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The NaH + Al + 0.02CeCl3 system has been studied by high-resolution X-ray synchrotron diffraction and transmission electron microscopy (TEM), after planetary milling under hydrogen and hydrogen (H) cycling. Isothermal absorption kinetics were determined at 150 °C, and compared with the NaH + Al + 0.02TiCl3 system, indicating that CeCl3 and TiCl3 are equally effective additives, with CeCl3 preferred on the basis of hydrogen storage capacity. After milling, AlCe contains 100% of the Ce. After the first H absorption, we observe two Al1-xCex phases. The first, AlCe, contains ca. 60% of the originally added Ce atoms. The AlCe phase observed after milling and H cycling is chemically disordered, with complete exchange between the Al and Ce sublattices occurring, yielding zero intensity in ordering reflections such as (100). In the absorbed state after H cycling, the remaining 40% of Ce atoms are contained in a cubic Al1-xCex phase not previously observed in the Al-Ce phase diagram. Indexing yields a primitive cubic unit cell of dimension 7.7111 A°, in space group P23. Lineshape analysis indicates the AlCe and unknown cubic Al1-xCex phases are ca. 35 nm and 30 nm in dimension respectively. High resolution TEM imaging confirms that both Al1-xCex phases are embedded on the NaAlH4 surface, and localised energy dispersive X-ray spectroscopy (EDS) indicates a ca. 2:1 Al:Ce ratio for the unknown cubic Al1-xCex phase. |
| first_indexed | 2025-11-14T07:20:49Z |
| format | Journal Article |
| id | curtin-20.500.11937-17306 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:20:49Z |
| publishDate | 2011 |
| publisher | Elsevier Ltd |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-173062017-09-13T16:08:12Z Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system Pitt, Mark Paskevicius, Mark Webb, C. Sorby, M. Delleda, S. Jensen, T. Hauback, B. Buckley, Craig Gray, E. Mechanical milling Synchrotron radiation - Hydrogen storage Aluminium alloys Nanocrystalline materials The NaH + Al + 0.02CeCl3 system has been studied by high-resolution X-ray synchrotron diffraction and transmission electron microscopy (TEM), after planetary milling under hydrogen and hydrogen (H) cycling. Isothermal absorption kinetics were determined at 150 °C, and compared with the NaH + Al + 0.02TiCl3 system, indicating that CeCl3 and TiCl3 are equally effective additives, with CeCl3 preferred on the basis of hydrogen storage capacity. After milling, AlCe contains 100% of the Ce. After the first H absorption, we observe two Al1-xCex phases. The first, AlCe, contains ca. 60% of the originally added Ce atoms. The AlCe phase observed after milling and H cycling is chemically disordered, with complete exchange between the Al and Ce sublattices occurring, yielding zero intensity in ordering reflections such as (100). In the absorbed state after H cycling, the remaining 40% of Ce atoms are contained in a cubic Al1-xCex phase not previously observed in the Al-Ce phase diagram. Indexing yields a primitive cubic unit cell of dimension 7.7111 A°, in space group P23. Lineshape analysis indicates the AlCe and unknown cubic Al1-xCex phases are ca. 35 nm and 30 nm in dimension respectively. High resolution TEM imaging confirms that both Al1-xCex phases are embedded on the NaAlH4 surface, and localised energy dispersive X-ray spectroscopy (EDS) indicates a ca. 2:1 Al:Ce ratio for the unknown cubic Al1-xCex phase. 2011 Journal Article http://hdl.handle.net/20.500.11937/17306 10.1016/j.ijhydene.2011.04.092 Elsevier Ltd restricted |
| spellingShingle | Mechanical milling Synchrotron radiation - Hydrogen storage Aluminium alloys Nanocrystalline materials Pitt, Mark Paskevicius, Mark Webb, C. Sorby, M. Delleda, S. Jensen, T. Hauback, B. Buckley, Craig Gray, E. Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title | Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title_full | Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title_fullStr | Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title_full_unstemmed | Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title_short | Nanoscopic Al(1-x)Ce(x) phases in the NaH + Al + 0.02CeCl(3) system |
| title_sort | nanoscopic al(1-x)ce(x) phases in the nah + al + 0.02cecl(3) system |
| topic | Mechanical milling Synchrotron radiation - Hydrogen storage Aluminium alloys Nanocrystalline materials |
| url | http://hdl.handle.net/20.500.11937/17306 |