The structural evolution and optical properties of Mg1-xZnxAl1.8Cr0.2O4 pink ceramic pigments

Abstract In this work, pink ceramic pigments based on the composition of Mg 1-x Zn x Al 1.8 Cr 0.2 O 4 (x = 0.0,0.3,0.5,0.7,1.0) were synthesized by using a gel polymerization method. We focused on studying the effect of A-site ion doping on the random cation distribution, microstructure and optical absorption performance. Field Scanning electron microscopy (FESEM), X-ray diffraction (XRD) and the Rietveld refinement method with a GSAS program were applied for micromorphology and cation distribution analyses. The optical performance of the pigments was studied by UV–vis and CIE L*a*b* spectrophotometry. All samples had a single spinel phase within the calcination temperature range of 800 °C–1400 °C and the primary grain size of the synthesized pigments were approximately 0.5–1 μm. The ion distribution in the tetrahedron and octahedron was largely dependent upon the calcining temperature and composition. The oxygen parameter, cell parameter, and T-O and M-O band lengths also varied with the cation distribution, leading to a change in the spinel structure and octahedron crystal field parameter and ultimately changing the optical absorption properties of the synthetic pigments. This study lays the foundation for subsequent studies of colour modification in ceramics.