Novel Cu2+-Fe3+ co-doped LaAlO3 ceramic with high infrared radiation performance

Abstract

A novel high-emissivity Cu2+-Fe3+ co-doped LaAlO3 ceramic has been prepared by a solid-phase reaction technology at high temperature. The effect of the doping ratio (0.25 ≤ n(Cu2+)/n(Fe3+)≤ 1.0) on the infrared radiation (IR) properties of LaAlO3 ceramics was investigated systematically, and the mechanism of enhanced emissivity was revealed. The result shows that Cu2+-Fe3+ co-doping can substantially improve the IR performance of LaAlO3 ceramics. In the range of 0.25 ≤ n(Cu2+)/n(Fe3+) ≤ 0.75, the emissivity of LaAlO3 ceramics increases steadily with the doping ratio. When n(Cu2+)/n(Fe3+) = 0.75, the specimen has the largest emissivity of 0.83 and 0.82 in the 1.0–2.5 µm and 2.5–14 µm bands respectively, achieving an enhancement of 315% and 116% than pure LaAlO3. The improved IR properties of Cu2+-Fe3+ co-doped LaAlO3 ceramics can be attributed to enhanced impurity energy level absorption, free carrier ion absorption and lattice vibration absorption. These high emissivity Cu2+-Fe3+ co-doped LaAlO3 ceramics are non-toxic, non-hazardous and low-cost, exhibiting promising application potential in the field of energy-saving for thermal equipment.