The temperature-dependent electricity and emissivity properties of La0.67Ca0.33−xSrxMnO3 compounds

The perovskite structure manganese oxides La0.67Ca0.33−xSrxMnO3 (x = 0, 0.03, 0.05, 0.08, 0.10, 0.13, 0.15) were synthesized by conventional solid-state reaction. The crystal structure, temperature-dependent electrical resistance and infrared reflectivity as well as total hemispherical emissivity properties of the prepared compounds were systematically investigated. The results indicate that all doped compounds have obvious metal-insulator transition when the temperature increases in a certain range. When the doping level x is equal to 0.03, 0.05 or 0.08, the metal-insulator transition temperature can be adjusted to 0 °C-10 °C and the variation of total hemispherical emissivity exceeds 0.45 ranging from −50 °C to +50 °C. All the properties mentioned above enable the compounds to show large application prospects on the thermal control systems of satellites.