Comparative Study on the Effect of Heat Treatment Temperatures on Colorimetric Properties of CoFe2O4 Nanoparticles and CoFe2O4/SiO2 Nanocomposites

In this paper, a comparative study on the effect of different heat treatment temperatures, i.e., 400, 500, 600 and 700 ?C on colorimetric properties of CoFe2O4 nanoparticles has been done for the first time. Then, the mentioned Co-Fe mixed oxide pigments are dispersed in an amorphous silicon oxide matrix to form CoFe2O4/SiO2 nanocomposites. In the next step, the optical properties of nanocomposites treated at different temperatures are investigated and compared with those of nanoparticles. Results show that increasing the treatment temperature from 400 ?C to 700 ?C leads to more neutral nanoparticles and nanocomposites, while the lightness attributes of them behave reversely. Besides, the gradient of lightness variation in nanoparticles is higher than that of nanocomposites. Meanwhile, regarding to the calculated color difference values, it is found that the colorimetric variations between nanoparticles and nanocomposites increase by increasing the treatment temperature.