Influence of the Ni/Mg Ratio on the Colour of Spinel Pigments Prepared by a Modified Sol – Gel Method

Abstract

ABSTRACT. This paper focuses on the synthesis and analysis of some spinelstructured, ceramic pigment nanopowders (Mg(1-x)NixAl2O4) using a modified sol -gel method. This study emphasizes the influence of the Ni/Mg ratio and that of the thermal treatment on the properties of the obtained powders. The behavior of the dried gels during calcination was studied by differential thermal analysis. The formation of the spinel structure after calcination was analyzed using x-ray diffraction. The colour of the powders was characterized by UV -VIS spectroscopy, determining the absorption spectra. In addition, the trichromatic coordinates were determined, and the corresponding pigment positions were fixed on the chromaticity diagram.