Infrared emissivity study of Hafnium boride based on first principles

Abstract

Hafnium boride (HfB2), as an electrically conductive ceramic material with excellent properties such as high conductivity, high temperature resistance and low infrared emissivity. In this paper, the infrared low emissivity properties of HfB2 materials are investigated based on the first principles. It is found that increasing the free electron concentration and decreasing the electron scattering can further reduce the infrared emissivity of HfB2 materials. The experimental results demonstrate that electron scattering can be effectively reduced by increasing the thickness of the film, thus lowering the IR emissivity. In addition, roughening the substrate can reduce the IR specular reflectivity of the film. With the increase of substrate roughness, the specular reflectivity of the HfB2 film in the IR laser band (λ = 10.6 μm) is reduced from 0.85 to 0.36 while the IR emissivity is kept low (<0.28), which is of great significance to reduce the return intensity of laser detection and thus to achieve multi-spectral compatibility of stealth.