One-Pot Microemulsion Synthesis of NaYF4 : Yb3+, Ho3+ @ Au

Rare earth fluoride nanomaterials and their precious metal complexes have unique optical, electrical and magnetic properties, which have been widely used in biomarker, optical storage, display and security. It has become one of the hotspots in the field of materials science. In this paper, the NaYF4 : Yb3+, Ho3+, NaYF4: Yb3+, and Ho3+ @Au composites were prepared by using microemulsion method. The results show that NaYF4 Yb', Ho' @Au composites were directly formed in the microemulsion system. The XRD shows that the NaYF4: Yb3+, Ho3+ is cubic phase, and there is no impurity peaks. Moreover, the diffraction peaks of NaYF4 Yb3+, Ho3+ @Au contain both NaYF4 and Au. It can be seen from the SEM that the nanoparticies are uniform spherical whose particle size is about 58 nm. In the up-conversion spectra, the high luminous intensity at 484, 682 and 767 nm are corresponding to S-5(2) -> (5)1(8), F-5(5) -> (5)1(8), S-5(2) -> L-5(7) transition of Ho3+.