| Автор | A D Franklin |
| Автор | J M Crissman |
| Автор | K F Young |
| Дата выпуска | 1975-04-21 |
| dc.description | Measurements are reported of the temperature dependence of EPR lifetime broadening in the spectrum of Gd<sup>3+</sup> ions in tetragonal sites in CaF<sub>2</sub> and of dielectric and anelastic relaxation in similar specimens. Concentrations ranged from 0.01 to 0.27 mol per cent GdF<sub>3</sub>, and the crystals were annealed in flowing He plus HF at various temperatures. The strongest relaxation modes (R<sub>I</sub>) arising from pairs formed from Gd<sup>3+</sup> ions plus trapped F<sup>-</sup> interstitials could be identified in both the dielectric (T<sub>1u</sub>) and the anelastic (E<sub>g</sub>) spectra. The rate constants are ln tau <sub>0</sub>=-32.83+or-0.24 ( tau <sub>0</sub> measured in seconds) and Q=0.44+or-0.005 eV, and are to be associated with jumps of the F<sup>-</sup> interstitials originating at the nearest-neighbour sites to the Gd<sup>3+</sup> ions. A low-temperature relaxation (Q approximately 0.2 eV) was observed in the anelastic spectrum with trigonal symmetry and also in the dielectric spectrum. It was found to consist of several components. It is argued contrary to earlier conclusions, that this relaxation is not an additional mode of the same centre giving rise to R<sub>I</sub>. A higher temperature relaxation (Q approximately 1.1 eV) was seen only in the anelastic spectrum, and was approximately isotropic. It too cannot be identified on the basis of present information. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Defect-complex reorientation processes in GdF<sub>3</sub>-doped CaF<sub>2</sub> |
| Тип | paper |
| DOI | 10.1088/0022-3719/8/8/027 |
| Print ISSN | 0022-3719 |
| Журнал | Journal of Physics C: Solid State Physics |
| Том | 8 |
| Первая страница | 1244 |
| Последняя страница | 1266 |
| Аффилиация | A D Franklin; Nat. Bur. Stand., Washington, DC, USA |
| Аффилиация | J M Crissman; Nat. Bur. Stand., Washington, DC, USA |
| Аффилиация | K F Young; Nat. Bur. Stand., Washington, DC, USA |
| Выпуск | 8 |
