Dual-phase nano-glass-ceramics for optical thermometry

Transparent bulk glass ceramics containing Yb/Er: YF3 and Cr:ZnAl2O4 dual-crystalline-phases were successfully fabricated via a glass crystallization strategy. X-ray diffraction, transmission electron microscopy and optical spectroscopy were used to investigate the microstructure of glass ceramics. Impressively, the detrimental energy transfers between Er3+ and Cr3+ were greatly suppressed because of the respective partition of Yb3+/Er3+ and Cr3+ dopants into YF3 and ZnAl2O4 crystals. As a consequence, Er3+ up conversion and Cr3+ down-shifting emissions were simultaneously enhanced. To explore their possible application in optical thermometry, temperature-dependent fluorescence intensity ratio of the thermally coupled emitting states of Er3+ (H-2(11/2), S-4(3/2)) and temperature-dependent fluorescence lifetime of Cr3+ (E-2, T-4(2)) in the Yb/Er/Cr triply doped dual-phase glass ceramics were systematically studied. Using the fabricated glass ceramics as the optical thermometric medium, the temperature sensitivities can reach as high as 0.30%K-1 at 585 K for Er3+ and 0.61%K-1 at 410K for Cr3+, respectively. (C) 2015 Elsevier B.V. All rights reserved.