Development of a β-LiAlSi2O6:Cr-based Ceramic Pigment by Proteic Sol-Gel Process Using Gelatin: Synthesis and Characterization

A novel pigment of β-LiAlSi2O6 :Cr ceramic was developed by a partial proteic sol-gel process, using gelatin as a ligand. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and visible and near-infrared diffuse reflectance spectroscopy (vis-NIR DRS) were performed. XRD results confirmed that the crystal structure of the lattice corresponded to β-LiAlSi2O6 (or β-spodumene), and the addition Cr3+ ions by doping did not interfere in the formation of this crystalline phase. EDS confirmed the homogeneous existence of Cr3+ dopant in β-LiAlSi2O6 particles. From the vis-NIR DRS, selective absorption of visible light wavelengths was identified in the bands of 425 nm and 600 nm, resulting in the perception of a yellowish-green color when β-LiAlSi2O6 is doped with Cr3+. CIE-XYZ colorimetric coordinates were generated to characterize the resulting colors. The obtained results demonstrated the viability of β-LiAlSi2O6 :Cr synthesis by a proteic sol-gel route and its great potential for obtaining a yellowish-green ceramic pigment.