Thermal Radiative Properties of (La,Sr)MnO₃ Thermochromic Coating Prepared by Sol-Gel Process

Thermochromic coating on yttria stabilized zirconia (YSZ) substrate was prepared by the sol-gel La_0.825Sr_0.175MnO₃ nanoparticles and the binder composed of terpineol and ethyl cellulose. The surface morphology and the variable emittance properties of coating in the infrared range was evaluated from infrared reflectance spectra at various temperatures. LSMO nanoparticles with size 200 nm are obtained by the sol-gel process. The coating sample shows a thermochromic behavior with the rise of temperature. The emittance of coating increases from 0.62 at 173 K to 0.88 at 373 K. When the sample surface root-mean-square roughness is 122 nm, its emittance variation increases from 0.43 at 173 K to 0.73 at 373 K.