A synchrotron study of Na2.27Ho7.73(SiO4)6O0.72
| Autor: | Luis Fuentes, Maria E. Fuentes, Lauro Bucio, Eligio Orozco, Ivonne Rosales |
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| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Acta Crystallographica Section E, Vol 65, Iss 5, Pp i33-i33 (2009) |
| Druh dokumentu: | article |
| ISSN: | 16005368 1600-5368 |
| DOI: | 10.1107/S1600536809011866 |
| Popis: | A well crystallized powder sample of sodium holmium orthosilicate oxyapatite, Na2.27Ho7.73(SiO4)6O0.72, was obtained after mechanical milling and thermal treatment at 1123 K. Crystal structure analysis was performed from the results of Rietveld refinement of the synchrotron diffraction data. As in other rare-earth orthosilicate apatites, sodium cations appear located sharing with holmium the 4f Wyckoff position at the center of a tricapped trigonal prism. In its turn, holmium almost fully occupies the 6h position at the center of a seven-coordinated pentagonal bipyramid. A small quantity of Na atoms was found at this site. No vacancies are present in the two independent crystallographic sites available for Ho and Na atoms. |
| Databáze: | Directory of Open Access Journals |
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