Abstract
Cr-doped calcium titanate (CaTiO3) pigments with prism-like shape were synthesized by a simple solvothermal process without any surfactants. The colouring mechanism and performance of Cr-doped CaTiO3 yellow pigment samples were investigated by X-ray diffraction, diffuse reflection spectroscopy, field scanning electron microscopy and colorimeter. When Cr-doping concentrations were 0.01–0.05% (mole fraction, the same below), solid solution formed so that the yellow pigments would have a CaTiO3 phase composition. The intensity of the yellow colour in the pigment samples was related to the presence of Cr ions. The optimum yellow pigment was achieved when the Cr-doping concentration was 0.03% mol. At a high temperature of 1280°C, Cr-doped CaTiO3 yellow sample provided a stronger and more intense colour as Cr ions dissolved into the stable CaTiO3 structure. This solvothermal preparation method provides a simpler way to synthesize a more colourful ceramic pigment that can be applied in ceramic decoration or inkjet printers.
