Enhanced photoluminescence and high temperature sensitivity in rare earth doped glass ceramics containing NaGd(WO4)2 nanocrytals

Abstract

NaGd (WO4)2 nanocrystals were successfully precipitated from silicate glasses for the first time and transparent glass ceramics were prepared. High diffraction peaks and well-resolved lattice fringes confirm the high crystallinity of NaGd (WO4)2 in the glass ceramics. The enhanced photoluminescence emission spectra, long fluorescence lifetime and the increased transition intensity ratio between 5D0→7F2 and 5D0→7F1 transitions of Eu3+ ions suggest that Eu3+ ions were incorporated into the precipitated NaGd(WO4)2 nanocrystals. Gradually enhanced upconversion emission spectra of Er3+ ions in the glass ceramics were observed with the increased thermal treatment time. The dependence of luminescence intensity ratio (LIR) on temperature was determined at the temperature range of 303 K–573 K. The maximum absolute sensitivity Sa is 0.012 K−1 at 542 K and the maximum relative sensitivity Sr is 1.178% at 303 K, which are attributed to the enrichment of Er3+ ions in the precipitated NaGd (WO4)2 nanocrystals and may be used for optical temperature sensors.