a b s t r a c tThe luminescent properties of Eu 2 + and Ce 3 + ions in Li 2 SrSiO 4 have been studied upon excitation in the 2-20 eV region. Based on the results of luminescent measurements, values of the crystal field splitting and the centroid shift of the Ce 3 + 5d configuration in Li 2 SrSiO 4 were found and compared with those of Ce 3 + ions in some other inorganic compounds. The Eu 2 + ions in Li 2 SrSiO 4 exhibit a broad band emission with a maximum at 576 nm, which is due to the 4f 6 5d-4f 7 transition. It was shown that the long-wavelength position of the Eu 2 + emission in Li 2 SrSiO 4 is caused by the large crystal-field splitting of the Eu 2 + 4f 6 5d configuration and relatively high degree of covalency of the Eu-O bond. The stabilization of Eu 2 + ions in Li 2 SrSiO 4 during the synthesis process requires a strong reducing agent. Two phenomenological approaches to explain the low stability of Eu 2 + in Li 2 SrSiO 4 are also discussed.
Spectral-luminescent properties of Eu 2+ ions in alkaline earth dilithiosilicates of composition MLi 2 SiO 4 (M = Ca, Sr, Ba) have been studied at 77 K. The reasons for the different positions of the Eu 2+ 4f 6 5d → 4f 7 emission band maximum in spectra of MLi 2 SiO 4 were found based on the obtained results. It was shown that the increase in the decay time of the Eu 2+ emission on going from CaLi 2 SiO 4 (0.41 μs) through BaLi 2 SiO 4 (0.64 μs) to Sr-silicate (1.11 μs) correlates with the shift of the emission maximum to longer wavelengths.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.