Radiative properties of thermochromic material with solar reflection films

Thermochromic material La_0.7Ca_0.2Sr _0.1MnO₃ is synthesized by solid-state reaction method. The solar absorptance, thermal emittance and reflectance are investigated. The research results indicated that the material has such a large solar absorptance value of 0.78 that it is disadvantageous for the thermal control material in space. Within the 97-373 K range, the thermal emittance of the material increases with the rise of temperature, and its variation amplitude is 0.6. To reduce the high solar absorptance and keep the variation amplitude of the emittance, solar reflection films are deposited onto the surface of the material. Experimental results show that the solar absorptance is reduced from the 0.78 of bare thermochromic material to the 0.27 of thermochromic material with solar reflection films, and the variation amplitude of the emittance is not affected by the films. In addition, irradiation suitability study of the material with solar reflection films for space application suggests that the variable emittance properties have no degradation undergoing the electrons and protons irradiation.