Influence of composition on near infrared reflectance properties of M-doped Cr(M=Ti,V) green pigments

Abstract

Ti-Al-V-doped Crgreen pigments could present a higher near-infrared (NIR) reflectance compared to pure Cr The amount of Ti and V introduced in the Crmatrix has been systematically varied respectively, in order to evaluate the effects of Ti and V contents on the NIR properties of the doped Cr For comparison, experimental reflectance measurements and mean- NIR reflectance (7802000 nm) of samples are given. The results reveal significant variations in the NIR region as a function of nominal composition for both Ti-doped Crand V-doped Cr Moreover, the NIR reflectance of a Ti-Al-V-doped Crpigment sample was measured. It has been found that it exhibits lower NIR reflectance compared to that reported in previous study. The correlations between electronic structural and spectroscopic features are discussed. For the Ti-doped Crsamples, the decrease of free carriers and the electronic transitions between defect energy levels within the band gap and the conduction band, could be responsible for the variable NIR reflectance. However, for V-doped Cr apart from light absorptions of free carriers, there are new light absorption peaks range from 1190 to 2000 nm, resulting in the variations of the NIR reflectance. © 2014 The Ceramic Society of Japan. All rights reserved.