摘要
The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses （x = 0 to 7 mol%） are investigated. Both Raman and IR spectra reveal that discrete phosphate species （[PO4]-3, [PO3O1/2]-2） 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 transi- tion temperature. According to the Judd-Ofelt intensity parameters （Ω2,Ω4, Ω6） of Er3＋, the asymmetry of local environment around Er3＋ becomes higher, and the bond covalency between Er3＋ and O2-decreases after P2O5 is introduced. In the emission spectra, photoluminescence intensity increases with increasing P2O5 concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er3＋ is dramatically changed, and the glass matrix becomes disordered.
The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses （x = 0 to 7 mol%） are investigated. Both Raman and IR spectra reveal that discrete phosphate species （[PO4]-3, [PO3O1/2]-2） 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 transi- tion temperature. According to the Judd-Ofelt intensity parameters （Ω2,Ω4, Ω6） of Er3＋, the asymmetry of local environment around Er3＋ becomes higher, and the bond covalency between Er3＋ and O2-decreases after P2O5 is introduced. In the emission spectra, photoluminescence intensity increases with increasing P2O5 concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er3＋ is dramatically changed, and the glass matrix becomes disordered.
