Environmentally benign novel green pigments: Pr1-xCaxPO4 (x = 0-0.4)

Rare earth based materials have recently attracted considerable attention as potential ecofriendly colourants for low temperature as well as high temperature applications. In the present study, we have synthesized a series of Ca-doped PrPO₄ compounds with the general formula, Pr_1-xCa_xPO₄ (x = 0-0.4 in steps of 0.1) and characterized the compounds by powder X-ray diffraction. All the compositions show a monoclinic monazite structure. The optical properties of the brilliantly coloured pigments L (brightness),a* (+ red- green),b* (+ yellow - blue) have been examined. These materials can find application as potential green colourants.