Effect of La content on infrared radiation performance of lanthanum-cerium oxides for high temperature application

Lanthanum-cerium oxides have promising potential for high temperature thermal protection. In this paper, lanthanum-cerium oxides with different La contents were synthesized by hydrothermal method and subsequent thermal treatment. The effect of La content on the microstructure and infrared emissivity were thoroughly studied. The infrared emissivity in 2.5–10 μm wavelength band of the samples increases with the doping of La content. Compared with pure CeO2, the emissivity of La2Ce2O7 increased 32.4% at 600 °C and 16.9% at 800 °C, respectively. The emissivity enhancement is attributed to the free carrier absorption and lattice absorption in wavelength band 2.5–10 μm. The enhanced emissivity is of great significance for the radiation thermal control in high temperature. •Lanthanum cerium oxides were controlled synthesized by hydrothermal method.•The infrared emissivity is enhanced in 2.5–10 μm band with La content increasing.•The emissivity enhancement of La2Ce2O7 is 32.4% at 600 °C and 16.9% at 800 °C.•The emissivity enhancement is due to the lattice and free carrier absorption.