Synthesis and spectral properties of Eu(3+)-doped YF(3) nanobundles

YF(3):Eu(3+) nanobundles were synthesized by a facile microemulsion method. Analysis of X-ray diffraction, scanning electron microscope, and transmission electron microscopy reveals that each nanobundle consists of numerous nanowhiskers with a mean length of similar to 500 nm and a mean diameter of similar to 2 nm. Under 393-nm excitation, the luminescence was dominated by (5)D(o) -> 7F(1) transition, indicating the inversion symmetry of Eu(3+) site. The luminescence intensity increased with increasing Eu(3+) concentration, up to about 30 mol%, and then decreased abruptly. The peak positions and spectral shapes of emissions were independent of Eu(3+) concentration. Finally, the critical distance of energy transfer was calculated. (c) 2008 Elsevier B.V. All rights reserved.