Enhanced infrared radiation of LaAlO3 ceramics via Co2+ doping

Infrared radiation (IR) ceramics are generally recognized as energy-saving materials for thermal equipment. In this work, as novel infrared radiation ceramics, Co2+-doped LaAlO3 ceramics were synthesized via a solid-phase reaction method, and the influence of the Co2+ doping concentration on the infrared emissivity of ceramics was systematically investigated. The original Al element position was replaced by Co in Co2+-doped LaAlO3, leading to lattice distortion, oxygen vacancy generation and the "Co2+→Co3+" transformation. The increase in doped Co content leads to enhanced impurity absorption, free carrier absorption and lattice vibration absorption, which significantly improve infrared emissivity. The average emissivity values in the 0.76–2.5 μm and 2.5–14 μm bands of the LaAl0.6Co0.4O3-δ specimen (40 mol% Co) are 0.89 and 0.86 respectively, which are 324% and 28% higher than those of pure LaAlO3. This novel Co2+-doped LaAlO3 ceramic with high infrared emissivity has significant application prospects for energy-saving applications of thermal equipment.