Sol-gel auto-combustion fabrication and optical properties of cobalt orthosilicate: Utilization as coloring agent in polymer and ceramic

Cobalt orthosilicate ceramic powder was fabricated successfully by using self-combustion of the modified gel in the presence of tartaric acid and glycine fuels. Violet coloring agent was obtained after the calcination of the obtained powder at 800 degrees C, 850 degrees C and 900 degrees C. The synthesized ceramic samples were investigated by thermal analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, Field Emission scanning electron micro-scopy, high resolution transmission electron microscopy, Energy Dispersive X-ray Analysis and diffuse reflectance spectroscopy. CIE-L*a*b* standard technique was utilized for the determination of color coordinates of the calcined products. Besides, the values of solar reflectance of the prepared samples were examined by using JIS standard method and band gaps of the calcined samples were determined. The synthesized ceramic samples show that the blue color on glaze while a violet color appeared on paint and polymer.