Excited states of Sm2+ in chloride host lattices

Emission spectra of Sm2+ at different temperatures in several chloride host lattices after excitation into the 4f55d1 levels are presented and compared. SrZnCl4 : Sm2+ shows broad 4f55d1→4f6 emission at room temperature while additional 5D0→7FJ emission is observed at lower temperatures. 4f55d1→4f6 as well as 5D0→7FJ emission is observed in BaZnCl4-I : Sm2+ at room temperature, investigations at lower temperatures show only 5D0→7FJ emission. In spite of the very similar [BaCl8] polyhedra in the crystal structures of BaZnCl4-I and BaZnCl4-II, the maximum of the 4f55d1→4f6 transition at room temperature is shifted to about 400 cm−1 in BaZnCl4-II. Again, 5D0→7FJ emission is observed in addition. At lower temperatures, the 5D1→7FJ emission is only detected. Finally, NaBaLaCl6 : Sm2+ shows only f→f transitions: 5D0→7FJ at room temperature and 5D1→7FJ at lower temperatures.