Back to Search
Start Over
Isolated centres versus defect associates in Sm3+-doped CeO2: a spectroscopic investigation.
- Source :
-
Journal of Physics D: Applied Physics . 2013, Vol. 46 Issue 27, p1-8. 8p. - Publication Year :
- 2013
-
Abstract
- The interactions between Sm3+ and oxygen vacancies in CeO2 are probed by the use of tuneable laser excited time-resolved photoluminescence and Raman spectroscopies. It is found that Sm3+ (with doping concentrations of 0.1, 0.3, 1 and 5 wt%) substitutes largely for Ce4+ in sites with cubic symmetry and the corresponding emission is sensitized via the Ce4+-O2- charge-transfer band of CeO2. It is established from the photoluminescence spectra measured at long delay after the laser pulse that the local environment around cubic Sm3+ centres is not changed with concentration and ceria size. In addition to cubic symmetry Sm3+ centres, low-symmetry Sm3+ centres tentatively assigned to the Sm3+-oxygen vacancy associates of nearest-neighbour type are also observed. Their emission is preferentially excited via the weak f-f absorption transitions of Sm3+. A relatively strong concentration-induced quenching of Sm3+ emission was inferred from the decrease in the average emission lifetimes from 2.1 ms (0.1 wt%) to 0.87 ms (5 wt%). The local environments of Sm3+ and Eu3+ in CeO2 are also compared on the basis of their emission spectra and decays. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00223727
- Volume :
- 46
- Issue :
- 27
- Database :
- Academic Search Index
- Journal :
- Journal of Physics D: Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 90149221
- Full Text :
- https://doi.org/10.1088/0022-3727/46/27/275302