Temperature and host dependence of the transition interference between f–f and f–d transitions of Sm2+ in matlockites

Abstract

The absorption spectra of Sm2+ doped in MFX (M=Sr, Ba; X=Cl, Br) crystals were studied within the range of 20,000–35,000cm−1 as a function of temperature and host. The absorption bands observed were described with a simple model developed by Wood and Kaiser using group theory. The temperature and host dependence on the 7F0→5D3 Fano resonance lines were investigated. BaFCl:Sm2+ system showed a “normal” 7F0→5D3 transition at 4K in spite of similar crystal structure and absorption profile with other MFX hosts. New Fano resonances were observed in the absorption spectra at higher energies (23,000–25,000cm−1) for all MFX:Sm2+ systems at 4K which persist up to room temperature. Preliminary energy level calculation showed that these resonance lines involve the interaction between higher excited 5LJ states of 4f6 configuration and 4f55d1 configuration.