Synthesis of La2NiO4 by the molten salt method and its infrared radiation properties

The layered perovskite structure material La2NiO4, which is a material with better infrared radiation properties, was synthesized successfully at 950 oC and above by the molten salt method. The emissivity values of La2NiO4 were all above 0.973 in the 3-5 & mu;m waveband, which was due to the narrow band gap, and those in the 8-14 & mu;m waveband were all above 0.987. The force constants of La2NiO4 were calculated, and it was proven that higher infrared emissivity in the 8-14 & mu;m waveband corresponds to lower force constants. In addition, the high temperature chemical stability of La2NiO4 was studied and it was found that no chemical reactions occurred in La2NiO4at high temperature. The infrared emissivity of La2NiO4 treated at 1400 oC was tested. The results showed that the maximum attenuation rate of infrared emissivity was less than 0.40%, indicating that La2NiO4 still had excellent infrared radiation properties after heat treatment. & COPY; 2023 Elsevier B.V. All rights reserved.