Color Properties of Eu-, Pr-doped and Codoped CeO₂

Abstract

Eu- and Pr-doped and codoped ceria Ce_1−x−yEu_xPr_yO_2−δ (x = 0, 0.01; y = 0, 0.0005) powder samples were synthesized by a coprecipitation method. The samples were characterized by XRD, color measurement, and UV-Vis diffuse reflectance spectroscopy. X-ray diffraction data indicated the formation of solid solution with fluorite-type structure. Pr doping to CeO₂ resulted in the brown color, although Eu-doped CeO₂ showed the same yellow as CeO₂. Eu- and Pr-codoped ceria of Ce_0.9895Eu_0.01Pr_0.0005O_2−δ showed brown color and the color change under light irradiation. The UV-vis spectra suggested photochromic properties.