Luminescence properties of Eu 2+ and Ce 3+ ions in calcium lithio-germanate Li 2 CaGeO 4
| Autor: | B.I. Zadneprovski, A. S. Voloshinovskii, Gregory Stryganyuk, I. V. Berezovskaya, S. M. Levshov, N. P. Efryushina, I.I. Seifullina, V. P. Dotsenko, E.E. Martsinko |
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| Rok vydání: | 2013 |
| Předmět: |
Lanthanide
Materials science Process Chemistry and Technology Doping Analytical chemistry Mineralogy Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion symbols.namesake Crystal field theory Stokes shift Materials Chemistry Ceramics and Composites symbols Germanate Luminescence Excitation |
| Zdroj: | Ceramics International. 39:6835-6840 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2013.02.015 |
| Popis: | The Eu 2+ -doped Li 2 CaGeO 4 samples have been prepared by the solid state reaction method and by thermolysis of the complex precursor. It was shown that Eu 2+ ions in Li 2 CaGeO 4 exhibit an intense emission with a maximum at 473 nm. The Stokes shift (820 cm −1 ) and full-width at half-maximum (1415 cm −1 ) of the emission band are close to those of the Eu 2+ emission in Li 2 CaSiO 4 . Values of the crystal field splitting and the centroid shift of the Ce 3+ 5d configuration in Li 2 CaGeO 4 were also determined and compared with those of Ce 3+ ions in Li 2 CaSiO 4 . Although the spectral positions of the Ce 3+ lowest excitation band for Li 2 CaRO 4 (R=Si, Ge) are practically the same, the magnitudes of the Ce 3+ crystal field splitting appeared to be unexpectedly very different. This effect is tentatively attributed to a strong distortion of the calcium site in Li 2 CaSiO 4 caused by the presence of the trivalent lanthanide ion. |
| Databáze: | OpenAIRE |
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