Effects of Some Cations on the Reflectivity of Complex Cobalt Blue Pigments

On the basis of analyzing crystal structure and coloring mechanism of the cobalt blue pigment, new kinds of complex cobalt blue pigments with excellent reflectivity properties were synthesized by using the chemical coprecipitation method to draw Zn2 ,Mg2 and La3 , Y3 doping cations into CoAl_2O_4 crystal cell. The increase of reflectivity properties is 30.8% at 450nm and -33.3% at 600nm comparing with undoped CoAl_2O_4 respectively. Considering the effects of doping cation type and content on reflectivity properties, a conclusion has been drawn that the main mechanism of reflectivity properties in alteration of complex cobalt blue pigments caused by doping cations is Co2 3d electronic energy level variation due to lattice distortion.