Synthesis and Fluorescence of Neodymium-Doped Barium Fluoride Nanoparticles

Abstract

Reverse microemulsions were used to synthesize barium fluoride doped with 0−65 mol % neodymium. Although the products were polydisperse, average particle sizes below 100 nm were achieved. XRD analysis showed that powders with 0−10 mol % Nd were single phase, while samples with dopant levels of 10−50 mol % contained two phases. Products with more than 50 mol % Nd were amorphous by XRD. Fluorescence of Nd:BaF2 showed an unusually high threshold for concentration quenching as well as very short lifetimes compared to those of bulk samples. The use of a cosurfactant and variation in reaction conditions provided control over particle size; smaller particles resulted by limiting the aqueous volume while simultaneously increasing the amount of cosurfactant for a given concentration of reactants.

PMMA Coated BaF2:Er3+Nanoparticles via a Novel One-Step Reverse-Emulsion Polymerization Process

“…The peaks broadening may be related with the Er 3+ doping concentrations in the nanoparticles. 16 In addition, the ICP data shows also that there are no other elements in the nanoparticles and the ratio of erbium to barium is about 12 mol%, which is consistent with the starting ratio. Figure 2 shows the TEM images of uncoated and PMMA coated BaF 2 :Er 3+ nanoparticles.…”

“…15 The peaks for ErF 3 are not seen in the XRD patterns, suggesting that the nanoparticles are not a core of ErF 3 surrounded by BaF 2 or nanocrystals of ErF 3 embedded in BaF 2 and that probably, Er 3+ ions substitute partly for the Ba 2+ and get into the lattice. 16 The particle sizes can be estimated by using Scherrer formula to be 11.8 nm and 23.5 nm for uncoated and PMMA coated BaF 2 :Er 3+ particles, respectively, indicating that BaF 2 :Er 3+ particles were coated by PMMA. Compared to the standard pure BaF 2 pattern, the excursion of the diffraction peaks in Figure 1(a), which has also been found in Er…”

Size, shape-controlled Synthesis of BaSiF6 nanostructures in a hydrothermal process

“…BaSiF 6 is an ideal material for host material that displaying unique luminescence properties when activated by rare-earth ions [4,5]. Recently, studies on fluorides nanoparticles have shown that nanoscale fluorides exhibit enhanced luminescence and photomagnetic properties [6,7]. However, to the best of our knowledge, studies on BaSiF 6 crystal is still at bulk levels, and no work has dealt with its nanosized structures.…”

Highly Efficient Fluorescence of NdF3/SiO2 Core/Shell Nanoparticles and the Applications for in vivo NIR Detection

“…[21] While recent literatures have demonstrated that in some NPs, fluorescent RE ions have unusual thresholds (even near 50 mol %) for the concentration effect. [22][23][24] This provides new possibility for improving fluorescent RE materials, however, it is still unclear whether there exists some RE NPs which are free from the concentration quenching effect. In this work, we developed NdF 3 /SiO 2 core/shell NPs, which demonstrated highly efficient fluorescence in vivo due to the successful suppressions of these two energy-loss effects as well as satisfying the above-mentioned spectral requirements.…”

“…Due to the match of their energy levels, the eventual energy transfers from the RE ions to a defect where non-radiative decay occurs. [36] In nanomaterials, such nonradiative energy transfer only occurs within one particle due to the hindrance of the particle boundary, [22,24] so quenching often occurs at much higher ion concentration compared with that in their bulk counterparts. Further, if the defect concentration is low enough in the nanomaterial, due to the physical volumetric constrains of the nanomaterial (10…”