Colorimetric study of black (Fe,Cr)₂O₃ pigment synthesis reaction: relation between chromatic coordinates and synthesis conditions

摘要

Samples of black (Fe,Cr)₂O₃ pigment were prepared from a starting mixture of Fe₂O₃ and Cr₂O₃ (50:50 by weight) at five temperatures between 1273 and 1423 K, using synthesis times ranging from 0 to 9 h. The influence of synthesis temperature and time on the chromatic coordinates of the pigment samples was established, and their chromatic coordinates were determined. On the basis of the experimental results, a single empirical correlation was obtained between each of the chromatic coordinates and the mass fraction in solid solution of the same composition as the starting oxide mixture present in each pigment sample.