Compositionally related glasses and ceramics of the Na$ sb2$O$ cdot$CaO$ cdot$Al$ sb2$O$ sb3 cdot$TiO$ sb2 cdot$SiO$ sb2$ system (sphene glass-ceramics) doped with Eu$ sp{3+}$ were examined using site-selective spectroscopic techniques (FLN). In sphene glass-ceramics, Eu$ sp{3+}$ preferentially partitions into the crystalline sphene phase. The partition ratio is concentration dependent, decreasing at higher concentrations, because of the limited solid solubility of Eu$ sp{3+}$ in sphene. The concentration occurs at the time of phase separation; Eu$ sp{3+}$ preferentially enters the more ionic (CaO, TiO$ sb2$)- rich droplet phase which eventually becomes sphene. In sphene, Eu$ sp{3+}$ substitutes for Ca$ sp{2+}$ appearing in three different sites caused by associated charge compensation defects. From an analysis of the FLN spectra of the different glasses, the framework for a model describing the coordination shell of Eu$ sp{3+}$ in oxide glasses is developed. The model suggests that Eu$ sp{3+}$ behaves as a network forming ion or quasi-molecular complex. The model is used to explain qualitative features of Eu$ sp{3+}$ FLN spectra including the dependence of the clustering of points of the major crystal field parameter ratios plot on the relative number of non-bridging oxygen ions and Eu$ sp{3+}$ ions in the glass.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75764 |
| Date | January 1988 |
| Creators | Belliveau, Thomas F. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000660138, proquestno: AAINL46137, Theses scanned by UMI/ProQuest. |
Page generated in 0.0022 seconds