A new thermal insulation ceramic pigment: Ce-doped Y3Al5O12 compounds combined with high near-infrared reflectance and low thermal conductivity

In this work, we explored NIR reflectivity and thermal conductivity of Y3-xCexAl5O12 compounds (x = 0.05, 0.1, 0.15, 0.2) as thermal insulation pigments. The test results show that the phase structure still retained the cubic phase and the morphology presents a curved worm-shaped. Also, cerium occurs in its mixed-valence state (+3, +4) in the Ce-doped Y3Al5O12. The prepared compounds registered a high value of NIR solar reflectance in 700-2500 nm of light (76.47%-90.06%), and the variation in NIR reflectivity value was expounded in terms of free carrier concentration and the electron trap. The ceramic materials added with the Ce-doped Y3Al5O12 pigments exhibited a lower thermal conductivity (< 0.3796 W/mk), compared with other conventional ones. Moreover, the composition displayed bright yellow colors, corresponding to the transition absorption of Ce3+ in the blue region from 4f to 5d. Application studies proved that the inner surface temperature of the ceramic substrate prepared with the synthesized pigment is 7.5 degrees C lower than the ordinary ceramic of the same color. This type of yellow ceramic pigment with optimal NIR reflectivity and low thermal conductivity exhibited potential applications in insulating ceramics. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the NIR reflectivity and thermal conductivity of Ce-doped Y3Al5O12 compounds as thermal insulation pigments, showing high NIR reflectance and low thermal conductivity. The yellow ceramic pigment with optimal NIR reflectivity and low thermal conductivity exhibited potential applications in insulating ceramics.