Configurational effects in the nonradiative 5D2 − 5D1 transition processes of Sm2+ in BaFClxBr1−x mixed crystals

The nonradiative 5D2−5D1 transition processes of Sm2+ in BaFClxBr1−x mixed crystals are investigated by using spectroscopic techniques in the thermal range 15–110 K. We found that theSm2+ centers in different local configurations have different nonradiative 5D2−5D1 transition rates due to the indirect processes which occur through the 4f55d band as intermediary. This characteristic leads to the fact that the inhomogeneous spectral distribution is strongly temperature dependent. It is observed that the different nonradiative rates are caused by the different positions of the low-lying 4f55d states of the Sm2+ ions in local configurations.