Preparation of Eu-Doped Y2O3 Luminescent Nanoparticles in Nonionic Reverse Microemulsions

In this study, Y(2)O(3):Eu luminescent nanoparticles were prepared by precipitation of aqueous yttrium nitrate/europium nitrate solution using ammonium hydroxide in the reverse microemulsions based on polyoxyethylene (5) nonylphenyl ether/polyoxyethylene (9) nonylphenyl ether, cyclohexane, and water. With Eu-doped Y(2)O(3) nanoparticles obtained, particle size, shape, chemical composition, crystalline formation rate, crystallinity, and photoluminescence were measured and compared with those of particles formed by a bulk precipitation method. The nanoparticles synthesized in microemulsion showed a narrow size distribution, spherical shape, fast crystalline formation rate, high crystallinity, and strong photoluminescence. This stronger photoluminescence of particles formed in a microemulsion might be attributed to more densely packed particles with very few voids and higher crystallinity at a relatively low temperature than those synthesized through a bulk precipitation method. Copyright 2000 Academic Press.