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| Content Provider | Royal Society of Chemistry (RSC) |
|---|---|
| Author | Lucas, Valérie Théry, Jeanine Aka, Gérard Viana, Bruno Vivien, Daniel Kahn-Harari, Andrée |
| Copyright Year | 1994 |
| Abstract | Single crystals of formula Na1.6(Al0.5–xGa0.5Crx)11O17.3(x= 0.002, 0.01), were grown by the flux evaporation method. The crystal structure study shows a β-alumina type structure with strong delocalisation of Na+ ions and an inhomogeneous distribution of Ga3+. In addition to a broad and intense emission band, corresponding to the Cr(4T2→4A2) transition, the fluorescence spectra present two other signals attributed to the Cr(2E→4A2) transition of various chromium species. At 700 nm, the emission band corresponds to a D3d symmetry site and at 709 nm to a CMs symmetry site occupancy. Cr3+ pairs are also identified. Time-resolved fluorescence spectroscopy and lifetime measurements are used to determine the Cr3+ site occupancy and to study Cr3+–Cr3+ interactions.These single crystals are doped by ionic exchange in molten salts, part of the sodium being replaced by Nd3+. Studies of the Cr3+ emission and Nd3+ excitation spectra indicate that efficient Cr3+→ND3+ energy transfer takes place in this material at 300 K. From the low-temperature Nd3+ decay profile, it is suggested that the transfer occurs mainly from the 4T2 Cr3+ state, and that Cr3+ pairs do not participate significantly in this transfer. |
| Starting Page | 907 |
| Ending Page | 913 |
| Page Count | 7 |
| File Format | |
| ISSN | 09599428 |
| Volume Number | 4 |
| Issue Number | 6 |
| Journal | Journal of Materials Chemistry |
| DOI | 10.1039/JM9940400907 |
| Language | English |
| Publisher | Royal Society of Chemistry |
| Access Restriction | Open |
| Subject Keyword | Fluorescence Chromium Absorption spectroscopy Ion exchange Sodium |
| Content Type | Text |
| Resource Type | Article |
| Subject | Chemistry Materials Chemistry |
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