Abstract : CePO 4 and CeO 2 nanoparticles were successfully synthesized by reflux method for different reflux timings 6 hrs and 12 hrs. Samples were subjected to Powder XRD, FTIR, SEM, UV-Vis, TG/DTA and PL studies. Powder XRD studies reveal that the crystallite sizes of CePO 4 and CeO 2 nanoparticles increases with increasing reflux time. The crystallite sizes of CeO 2 nanoparticles are smaller than CePO 4 nanoparticles which is evident from the peak broadening in XRD analysis. SEM images show that lots of agglomerations in CeO 2 nanoparticles when compared to CePO 4 nanoparticles. UV-Vis spectral studies indicate that the prepared CePO 4 and CeO 2 nanoparticles are highly transparent (~ 94%) in the entire UVVis range. The FTIR analysis confirms the presence of phosphate group in the prepared CePO 4 sample. The peaks corresponding to CeO 2 vibrations are seen in the FTIR spectrum of CeO 2 sample. The Photoluminescence (PL) studies of CeO 2 show two emission peaks around 395 nm and 412 nm, corresponding to violet emission, whereas the PL spectra of CePO 4 shows emission peaks at 487 nm and 547 nm corresponding to bluish green and green emissions. TG/DTA results show that in the case of CeO 2 nanoparticles, the samples prepared at a reflux timing of 6 hrs suffer greater weight loss than the samples prepared at a reflux timing of 12 hrs. But the reflux timing doesn't seem to have any influence on the thermal properties of CePO 4 nanoparticles
