High-temperature broadband infrared radiation from rare earth monosilicate-based ceramics

How to maximize the extraction of heat by infrared radiation while reducing the thermal conductivity to prevent heat transfer is the main challenge of radiative thermal management for emerging industrial and aerospace applications. Herein, we reported a high-temperature broadband high emissivity (Y0.5Lu0.5)2SiO5 ceramic with emissivity above 0.9 at room temperature and above 0.61 at elevated temperature of 1200℃ across the entire range of wavelength (1-14μm). Lu-doped rare earth monosilicate with high lattice entropy has a more complex electronic structure, boosting the emissivity of near-infrared wavelength (1-3 μm), as well as enhanced emissivity in the MIR range (3-14 μm) is derived from the lattice distortion and extra multi-mode vibrations induced by the substitutional doping of Lu3+ into the host lattice. Moreover, based on Stephen-Boltzmann law and energy conservation law found that the emissivity of rare earth monosilicate-based ceramics is negatively correlated with temperature, which may be due to the fact that rising temperature increases damping of phonon vibration of the ceramic lattice, reducing the ability of infrared absorption. This doped rare earth monosilicate ceramic has a high emissivity at high temperatures above 1200 °C, revealing immense potential in the radiation thermal protection field.