The structural and spectroscopic properties of Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2-x</sub>P<sub>2</sub>O<sub>5</sub> glasses (x=0 to 7 mol%) are investigated. Both Raman and IR spectra reveal that discrete phosphate species ([PO<sub>4</sub><sup>-3</sup>, [PO<sub>3</sub>O<sub>1/2</sub>]<sup>-2</sup>) with low polymerization degree can be formed in the silicate glass. These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network, resulting in an increase of the glass transition temperature. According to the Judd-Ofelt intensity parameters (Ω<sub>2</sub>, Ω<sub>4</sub>, Ω<sub>6</sub>) of Er<sup>3+</sup>, the asymmetry of local environment around Er<sup>3+</sup> becomes higher, and the bond covalency between Er<sup>3+</sup> and O<sup>2-</sup> decreases after P<sub>2</sub>O<sub>5</sub> is introduced. In the emission spectra, photoluminescence intensity increases with increasing P<sub>2</sub>O<sub>5</sub> concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er<sup>3+</sup> is dramatically changed, and the glass matrix becomes disordered.
© 2012 Chinese Optics Letters
(160.2750) Materials : Glass and other amorphous materials
Jia Ding, Youkuo Chen, Wei Chen, Lili Hu, and G. Boulon, "Effect of P2O5 addition on the structural and spectroscopic properties of sodium aluminosilicate glass," Chin. Opt. Lett. 10, 071602-071602 (2012)