The powder XRD patterns of the Ce0.95MxPr0.05xO2
(M = Mn and Si, x ranges from 0 to 0.05) pigments are shown
in Fig. 1. The intense and sharp peaks found in the diffraction
patterns reveal the crystalline nature of the powders. All
compounds crystallize with the cubic fluorite structure of CeO2
(space group – Fm3m, No. 225) and all the peaks are in good
agreement with the JCPDS card no. 34-394. Doping of small
amounts of praseodymium and Mn/Si in cerium oxide retains
the fluorite structure except minor variations in the d-spacings
as expected.