Synthesis, Colour and Optical Evaluation of Ceramic Powders in the System of Ceria-Zirconia-Terbia

Abstract

Ceria-zirconia-terbia solid solutions were synthesized by co-precipitation method. The powders were characterized by XRD, colorimetric assessment and UV-Vis diffuse reflectance. A solid solution phase structure was obtained for all of the samples heated at 900°C and belongs to cubic fluorite structure or distorted fluorite structure. It was found that the lattice size decreased with increasing Zr content in the range x = 0 to 0.8 in Zr_xCe_1-xO₂ and Zr_xCe_0.99-xTb_0.01O_2-δ. Diffuse reflectance spectra of the Zr_xCe_1-xO₂ solid solutions in the UV region showed the broad shoulder-type band at 320-350 nm, which was assigned to interband transitions in CeO₂ and additionally broader band in higher wave length region in solid solution. It was observed that Zr_xCe_1-xO₂ powder became deeper yellow depending on Zr content, and that the doping of Tb resulted in warm colour in CeO₂-ZrO₂ based solid solution. The powders in the system of Zr_xCe_1-xO₂ and Zr_xCe_0.99-xTb_0.01O_2-δ were possible pigments with environmental friendly properties toward future ceramic application.