SEM

Rare earth doped glass–ceramics containing NaLaF4 nanocrystals

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E. Elsts , G. Krieke, U. Rogulis, K. Smits, A. Zolotarjovs, J. Jansons, A. Sarakovskis, K. Kundzins

Oxyfluoride glasses 16Na2O–9NaF–5LaF3–7Al2O3–63SiO2 (mol%) activated with 3% terbium, dysprosium,
praseodymium and neodymium fluorides have been prepared and studied by differential thermal analysis,
cathodoluminescence, X-ray induced luminescence, X-ray diffraction, scanning electron microscopy
and energy dispersive X-ray spectroscopy. We found out that the presence of crystalline phase enhances
the X-ray induced luminescence intensity. X-ray induced luminescence is the most intense for the sample
activated with terbium and treated at 700 C, whereas the praseodymium and neodymium activated
samples have the fastest decay times.

Optical Materials xxx (2016) xxx–xxx

doi: 10.1016/j.optmat.2016.01.005

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Multicolor upconversion luminescence of GdVO4:Ln3þ/Yb3þ (Ln3þ ¼ Ho3þ, Er3þ, Tm3þ, Ho3þ/Er3þ/Tm3þ) nanorods

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Tamara V. Gavrilovic , Dragana J. Jovanovic,  Krisjanis Smits, Miroslav D. Dramicanin 

Lanthanide-doped GdVO4 nanorods that exhibit upconversion emission under 982 nm excitation have
been prepared by a facile room-temperature chemical co-precipitation method followed by a subsequent
annealing at temperatures of 600 C, 800 C and 1000 C. Multicolor upconversion emission, including
white, was achieved by tuning the concentrations of dopant lanthanide ions (Ho3þ, Er3þ, Tm3þ and Yb3þ)
in GdVO4. It is found that four GdVO4 samples emit light with the white chromaticity coordinates of
(0.326, 0.339), (0.346, 0.343), (0.323, 0.327) and (0.342, 0.340) respectively, under a single-wavelength
NIR excitation. These coordinates are very close to the standard equal energy white light coordinates
(0.333, 0.333) according to the 1931 CIE diagram. By varying dopant lanthanide concentrations in
nanorods it is possible to produce upconversion emission with colors between red (0.504, 0.369), green
(0.282, 0.577) and blue (0.142, 0.125) coordinates.

Dyes and Pigments 126 (2016) 1e7

doi:10.1016/j.dyepig.2015.11.005

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