| Popis: |
The effects of the surroundings on the emission properties of Sm2+ ion in inorganic crystals are probed by high pressure experiments as well as by chemical substitution. The sharp f-f emissions of Sm2+ under high external pressure enable us to study the pressure effect on the crystal field energy levels. A routine program allows to refine free ion and CFP by minimizing the differences between the observed and calculated energy levels. The variations of the F2, ξ parameters as a function of pressure were discussed relative to central field covalency and symmetry restricted covalency models. Using the formalism of the superposition model as a function of pressure, we have calculated intrinsic crystal field parameters. Emission lifetime measurements were performed as a function of temperature and pressure. The temperature dependent experiments can be described by a contribution of both radiative and non-radiative pathways which involve also the lowest f-d level. |
