Author/Authors :
S. and Alombert-Goget، نويسنده , , G. and Gaumer، نويسنده , , N. and Obriot، نويسنده , , J. and Rammal، نويسنده , , A. and Chaussedent، نويسنده , , S. and Monteil، نويسنده , , A. and Portales، نويسنده , , H. and Chiasera، نويسنده , , A. and Ferrari، نويسنده , , M.، نويسنده ,
Abstract :
Eu2O3–Al2O3–SiO2 monolithic xerogels doped with 2000 ppm Eu/Si and 5000 ppm Eu/Si, were prepared with different Al/Eu molar ratios: (a) 0, (b) 0.25, (c) 0.5, (d) 0.75, (e) 1, (f) 3, (g) 6, (h) 10, and (i) 15. The samples were investigated by photoluminescence spectroscopy. When we compare the spectra of the Al3+-co-doped xerogels with those of the samples without aluminum, several significant differences of the spectroscopic features appear: (i) the 5D0 → 7F0 transition exhibits a blue shift; (ii) the emission bands broaden; (iii) the relative amplitude among the different transitions changes as well as (iv) the splittings of the Stark components of the 5D0 → 7FJ transitions, and (v) the 5D0 level decay curves present a stretched exponential like profile. The results are discussed with the aim of assessing the effect of the Al/Eu molar ratio on the structural and spectroscopic properties of Eu2O3–Al2O3–SiO2 xerogels.
