Abstract:
New inorganic pigments having the general formula Ce1 (xþy)ZrxTayO2þd (x ranges from 0.15 to 0.2 and y
ranges from 0 to 0.05) displaying colors ranging from white to yellow have been synthesized by
a traditional solid-state route, as viable alternatives to lead, cadmium and chromium based yellow toxic
inorganic colorants. The products were characterized by X-ray powder diffraction, UV–vis diffuse
reflectance spectroscopy and CIE-L*a*b* 1976 color scales. The coloring mechanism is based on the strong
absorptions of the pigments in the visible region under 500 nm, which could originate from the additional
energy level between O2p valence band and the Ce4f conduction band by forming a hybrid orbital
of Ta5d and O2p. The designed yellow pigments consist of non-toxic elements and further found to be
thermally and chemically stable. The pigments were also found to be suitable candidates for the coloration
of plastics.
