Synthesis and Fluorescence of Neodymium-Doped Barium Fluoride Nanoparticles

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.