Sm3+-doped La2O3-Al2O3-SiO2-glasses: structure, fluorescence and thermal expansion

This paper reports on the effect of the chemical composition on the glass structure, the coefficients of thermal expansion and the fluorescence properties of Sm3+-doped La2O3-Al2O3-SiO2-glasses. The silica concentration was varied between 50 and 70 mol% and the La2O3:Al2O3 ratio between 50:50 and 30:70. The glass formation and the densities are evaluated and FTIR reflectance spectra, coefficients of thermal expansion and fluorescence lifetimes are determined. It is shown that high SiO2 concentrations and low La2O3:Al2O3 ratios result in relatively high fluorescence lifetime (2.19 ms, (4)G(5/2)) and low coefficients of thermal expansion (4.6 x 10(-6)/K). The coefficients of thermal expansion and the fluorescence lifetimes show a linear dependency on the ratio LaO3/2/(AlO3/2 + SiO2).