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

Abstract

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.

Keywords:
proteic sol-gel process; gelatin; β-spodumene; ceramic pigment