Characterization of MgxM2-xP2O7 (M = Cu and Ni) solid solutions

In this study, MgxM2-xP2O7 (M = Cu, Ni; 0 <= x <= 2) and Mg3-yNiy(PO4)(2) (0 <= y <= 3) compositions were synthesized by the chemical coprecipitation method and characterized by X-ray diffraction, UV-vis-NIR spectroscopy and CIE 1,5 a* b* (Commission Internationale de l'Eclairage L* a* b*) parameters measurements. Solid solutions with alpha-Cu2P2O7 and alpha-Ni2P2O7 structures and solid solutions with Ni-3(PO4)(2) structure were obtained from diphosphate and orthophosphate compositions respectively. lsostructurality of alpha-Ni2P2O7 and alpha-Mg2P2O7 structures enlarges the compositional range of solid solution formation respect to the MgxCu2-xP2O7 solid solutions one. The CIE L* a* b* parameters in MgxNi2-xP2O7 samples were obtained comparable with these parameters in others yellow materials suitable for ceramic pigments. Mg0.5Ni1.5P2O7 composition fired at 800 degrees C or 1000 degrees C is the optimal composition to obtain yellow materials with alpha-diphosphate structure in conditions of this study. (C) 2011 Elsevier Ltd. All rights reserved.