Spectroscopic properties Eu3+ doped and Tm3+/Yb3+ codoped oxyfluoride glass ceramics containing Ba2GdF7 nanocrystals

Transparent Eu3+ doped and Tm3+/Yb3+ codoped oxyfluoride glass ceramics were prepared and spectroscopic properties were investigated. The XRD and TEM results demonstrated the formation of Ba2GdF7 nanocrystals, and the reduction of the ratio β between 5 D 0 → 7 F 2 and 5 D 0 → 7 F 1 transitions of Eu3+ ions evidenced rare-earth ions incorporation into Ba2GdF7 nanocrystals. For Tm3+/Yb3+ codoped glass ceramic, unusual ultraviolet upconversion emissions from 6 P J → 8 S 7 / 2 transition of Gd3+ at 308 nm and 1 D 2 → 3 H 6 , 1 D 2 → 3 F 4 and 1 G 4 → 3 H 6 transitions of Tm3+ at 359 nm, 449 nm and 476 nm were observed under 980 nm excitation, respectively. And upconversion mechanism of Tm3+–Yb3–Gd3++ system was analyzed.