Investigation on radiative and optical properties of thermochromatic materials

The thermochromatic materials, of which phase transition temperature is near room temperature, are prepared by standard solid state reaction method. The influences of component fraction and doping element on the radiative and optical properties of the materials are studied. Based on the spectral reflectivity data of the materials, the optical constants are obtained through the Kramers-Kroning analysis. The result shows that the emissivity of the materials (La_0.7Ca_0.2Sr_0.1MnO₃ and La_0.825Sr_0.175MnO₃) present a sudden transition around the phase transition temperature, and the optical constants can be also adjusted by the change of doping level.