| Автор | M C Marco de Lucas |
| Автор | F Rodriguez |
| Автор | M Moreno |
| Автор | A Tressaud |
| Дата выпуска | 1994-08-01 |
| dc.description | Precise photoluminescence measurements have been carried out on RbCdF<sub>3</sub>:Mn<sup>2+</sup> in the 9-300 K range to explore the structural phase transition of the host lattice at T<sub>c</sub>=124 K using the first (M<sub>1</sub>) and second (M<sub>2</sub>) moments of the emission band together with the lifetime tau as probes. Aside from showing a sensitivity of M<sub>2</sub>(T) and tau (T) to the phase transition, the present data reveal that the curve M<sub>1</sub>(T) experiences a small but observable change of slope in the vicinity of T<sub>c</sub>. It is demonstrated that this jump, Delta <sub>t</sub>( delta M<sub>1</sub>/ delta T)<sub>P</sub>=0.22 cm<sup>-1</sup> K<sup>-1</sup>, is mainly associated with the increase experienced by the local thermal expansion coefficient below T<sub>c</sub>. The importance of both the implicit and explicit contributions to M<sub>1</sub>(T) is analysed throughout this work. Neither the luminescence nor the excitation spectrum shows any evidence of tetragonal distortion in the MnF<sub>6</sub><sup>4-</sup> complex. This fact is explained through the R<sub>ax</sub>-R<sub>eq</sub>=0 2 pm value (where R<sub>ax</sub> and R<sub>eq</sub> are the axial and equatorial Mn<sup>2+</sup>-F<sup>-</sup> distances) at 30 K, and the coupling coefficient V<sub>E</sub>=66 cm<sup>-1</sup> pm<sup>-1</sup> with the E<sub>g</sub> Jahn-Teller mode of MnF<sub>6</sub><sup>4-</sup>. Finally, we have found that this crystal exhibits photochemical reactions under UV light irradiation, leading to the formation of centres that transfer easily to Mn<sup>2+</sup> ions. These centres give rise to an intense absorption band at 310 nm, analogously to those previously formed under x-irradiation. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | The influence of a second-order phase transition on impurity luminescence: A study of RbCdF<sub>3</sub>:Mn<sup>2+</sup> |
| Тип | paper |
| DOI | 10.1088/0953-8984/6/31/034 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 6 |
| Первая страница | 6353 |
| Последняя страница | 6366 |
| Аффилиация | M C Marco de Lucas; Fac. de Ciencias, Cantabria Univ., Santander, Spain |
| Аффилиация | F Rodriguez; Fac. de Ciencias, Cantabria Univ., Santander, Spain |
| Аффилиация | M Moreno; Fac. de Ciencias, Cantabria Univ., Santander, Spain |
| Аффилиация | A Tressaud; Fac. de Ciencias, Cantabria Univ., Santander, Spain |
| Выпуск | 31 |
