Near-infrared solar reflectance and chromaticity properties of novel green ceramic pigment Cr-doped Y3Al5O12

Abstract

Y3Al5O12 as substrates accompanied by Cr3+ as dopant ions were prepared as new NIR reflective ceramic pigments. The structure verification of Cr3+ substituted Y3Al5O12 was conducted by FT-IR and XRD, and its particle morphology showed a combination of baseball-like and granular shapes via FE-SEM. The doped samples exhibited high NIR solar reflectance values ranging from 91.47% to 75.96%, which is inversely proportional to the Cr3+ concentration. The variation of the near-infrared reflectance was elucidated from the aspect of the carrier concentration and electron traps. The green tone of the Cr-doped Y3Al5O12 ceramic powders has concerned with its absorption peak in the UV–Vis region, originating from the energy level transition of 4A2g→4T1g and 4A2g→4T2g of Cr3+. Also, the new ceramic pigments possessed the characteristics of acid and alkali resistance (Δ E∗ ​< ​3), and high-temperature (1000 ​°C) resistance. The Cr-doped Y3Al5O12 pigments have the virtue of high NIR reflectance, pleasant green color and high tolerability, and are promising to become the colorant for blanks and glazes, which can make up for the inadequacy of a single material.