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 oC 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 in different temperatures are investigated and compared with those of nanoparticles. Results show that increasing of treatment temperature from 400 oC to 700 oC 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 by increasing of treatment temperature the colorimetric variations between nanoparticles and nanocomposites increase.