Er-doped YF3 nanoparticles were prepared from quaternary microemulsions of cetyltrimethyl ammonium bromide,n-butanol,n-octane and water with oil to water(mass percent of ω(CTAB)=19.04%,ω(n-butanol)=15.24%,ω(n-octane)=51.40%. The nanofluorides were characterized by X-ray power diffraction and infrared fluorescence spectroscopy. The results of XRD are in agreement with the PDF#74-911 of YF3. The average grain size is about 30 nanometer as estimated by Scherrer Formula. ESEM images show that the diameter of BaF2∶Er3+ nanoparticles is 35 nm. The emission of infrared fluorescence spectroscopy of the predominant peak is located at 1547 nm and the up-conversion optical properties measured with 980 nm laser diode show red and green emissions.
