Xusheng Qiao

Local vibration around rare earth ions in alkaline earth fluorosilicate transparent glass and glass ceramics using Eu3+ probe

Abstract By heat treating the alkaline earth fluorosilicate glass, transparent glass ceramics containing alkaline earth fluoride nanocrystallites were prepared. The luminescence spectra and phonon sideband associated with the Eu 3+ : 5 D 2 → 7 F 0 in glass and glass ceramics were investigated to analyze the local environment around Eu 3+ . Judd-Ofelt parameters were also calculated from emission spectra, which indicated that the Eu 3+ ions entered the precipitated CaF 2 , SrF 2 , and BaF 2 nanocrystallites. Heat treating could not pledge Eu 3+ ions to coordinate with F − in the precipitated MgF 2 nanocrystallites, owing to the smaller radius of Mg 2+ than that of Eu 3+ .

Preparation and Luminescence of Er3+ Doped Oxyfluoride Glass Ceramics Containing LaF3 Nanocrystals

Abstract Er 3+ doped transparent oxyfluoride glass ceramics containing LaF 3 nanocrystals were prepared and the up-conversion and near infrared luminescence behavior of Er 3+ in glasses and glass ceramics were investigated. With increasing heat-treating time and temperature, the size (varied from 0 to 19 nm) and crystallinity (varied from 0 to 47%) of LaF 3 nanocrystals in the glass ceramics are increased. The up-conversion luminescence intensity of Er 3+ ions in the glass ceramics is much stronger than that in the glasses and increased significantly with increasing heat-treating time and temperature. The near infrared emission of Er 3+ ions in the glass ceramics is found to be similar to that in the glasses.

Judd–Ofelt analysis and upconversion emission of Er3+–Yb3+ co-doped oxyfluoride glass ceramics containing LaF3 nanocrystals

Er3+–Yb3+ co-doped glasses and glass ceramics containing LaF3 nanocrystals were prepared and their absorption spectra obtained. The Judd–Ofelt parameters Ω t (t = 2, 4, 6) for f–f transition of Er3+, as well as spontaneous emission probabilities, branching ratios and radiative lifetimes for stimulated emission of each band were determined. Addition of Er3+ and Yb3+ ions into low-phonon energy LaF3 nanocrystals makes the upconversion emission of Er3+–Yb3+ co-doped glass ceramic much stronger than that of Er3+–Yb3+ co-doped glass.