Abstracts 2006

Abstract of Publication No. 561

Judith Grimm, Eva Beurer and Hans U. Güdel
Crystal Absorption Spectra in the Region of 4f-4f and 4f-5d Excitations in Tm2+-Doped CsCaCl3, CsCaBr3, and CsCaI3
Inorg. Chem. 45, 10905-10908 (2006)      Full Text (PDF)      DOI-Link     

Abstract: Low-temperature absorption spectra of single crystals of Tm2+-doped CsCaCl3, CsCaBr3, and CsCaI3 in the spectral range from 8700 to 47000 cm1 are presented. Weak sharp-line 4f-4f absorptions around 8800 cm1 are essentially independent of the nature of the halide. More-intense broad absorptions cover the region between 12000 and 47000 cm1. They are assigned to 4f-5d excitations and interpreted in terms of a simple qualitative picture taking into account the most important interactions. As a result of two counterbalancing effects, the onsets of the 4f-5d spectra are almost coincident in the three materials: The blue-shift of about 3000 cm1 between chloride and iodide resulting from the decreasing crystal field splitting of 5d is roughly balanced by the red-shift resulting from the reduced energy gap between the average energy of the 4f13 and the 4f125d1 electron configurations. The absorption helps the understanding of the most unusual light emission properties of these materials.

Last modified: 13.12.11 by Gabriela Frei