Novel nontoxic nanopigments based on zirconia and rare earth mixed oxides

Abstract

This paper embodies the result of the investigations carried out on the synthesis of zirconia-rare earth mixed oxide pigments: ZrCe 1-x Y x O 4-δ and ZrCe 1-x Pr x O 4-δ by the solution combustion method and their characterization by X-ray powder diffraction, transmission electron microscopy, energy dispersive spectrometric analysis, thermal analysis, reflectance spectral data and surface area measurements. The synthesized nano pigments possess low a and high b and exhibit yellow color when doped with Y and changes from yellow to orange-red color when doped with Pr, with increase in x values. These pigments show maximum reflectance of 90% when the wavelength is above 550 nm. Due to the homogeneity of the phase formed and resistance to water, acids and alkali, the rare earth mixed oxides developed are found to be promising candidates as nontoxic pigments.

Effect of coloration with various metal oxides on zirconia

“…A dopant is classically defined as an element incorporated in trace amounts to alter the chemical properties. Dopants are present in zirconia either as a distinct phase or as a solid solution . It is well established that dopants such as silica or alumina directly influence the grain morphology, microstructure, and stability of zirconia .…”