Eintrag weiter verarbeiten
Neutron and X-ray Diffraction Study on the Structure of Ultraphosphate Glasses
Gespeichert in:
| Zeitschriftentitel: | Zeitschrift für Naturforschung A |
|---|---|
| Personen und Körperschaften: | , , , , |
| In: | Zeitschrift für Naturforschung A, 52, 1997, 3, S. 259-269 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
Walter de Gruyter GmbH
|
| Schlagwörter: |
| Zusammenfassung: | <jats:title>Abstract</jats:title> <jats:p> The high real-space resolution of neutron diffraction experiments which is provided by use of the epithermal neutrons from spallation sources was exploited in order to differentiate the unlike P-O bonds existing in the PO<jats:sub>4</jats:sub> units of phosphate glass networks. The 2 P-O distance peaks, separated by about 12 pm, which were found in the zinc and the calcium ultraphosphate glasses studied are assigned to oxygen sites on bridging (O<jats:sub>B</jats:sub>) and terminal (O<jats:sub>T</jats:sub>) positions. The mean P-O distances are nearly invariable versus the growing metal oxide content which results from an elongation of the P-O<jats:sub>B</jats:sub> and P-O<jats:sub>T</jats:sub> bonds. The bond lengths which are known from the related crystal structures and from ab initio calculations show almost the same behaviour. The discussion of further details of the crystal structures leads to the conclusion that P-O<jats:sub>B</jats:sub> rather than P-O<jats:sub>T</jats:sub> distances should show more details in case of diffraction measurements of even higher real-space resolution. </jats:p> <jats:p>The change of the Zn-O coordination number from 6 to 4 versus increasing ZnO content, which was obtained in previous X-ray diffraction experiments, is confirmed by the recent combination of neutron and X-ray diffraction data. On the other hand, the Ca-O coordination number of about 6 is almost invariable.</jats:p> |
|---|---|
| Umfang: | 259-269 |
| ISSN: |
1865-7109
0932-0784 |
| DOI: | 10.1515/zna-1997-0305 |