The effect of Mg²⁺ doping on the infrared emissivity of LaCrO₃ perovskites

The infrared high emissivity ceramic material plays an important role in thermal protection of hypersonic vehicles. LaCrO₃, characterized by excellent thermal stability and high emissivity, can be applied as infrared high emissivity material. LaCrO₃ and Mg²⁺ doped LaCrO₃ were prepared via solid state reaction method. XRD analyses showed that LaCr_1-xMg_xO₃ (x = 0, 0.1, 0.2, 0.25, 0.3) were single-phase solid solutions. The doping-effect of Mg²⁺ on the infrared emissivity was investigated. In the range of 2.5–8 μm, the infrared emissivity of all doped materials had significant improvement, the average emissivity of materials increased from 0.66 to 0.83. In the range above 8 μm, the emissivity of all materials had a similar trend and compared to LaCrO₃, the emissivity of Mg²⁺ doped LaCrO₃ had little decrease.