Effects of sintering temperatures on the infrared emissivity of La0.7Sr0.3MnO3

La0.7Sr0.3MnO3 powders were fabricated by the traditional solid state reaction at different temperatures. The crystal structure, infrared transmittance spectra, resistivity and infrared normal emissivity ɛN in the range of 8–14 μm were examined using different methods. Effects of sintering temperatures on the infrared emissivity were investigated. It is found that the emissivity of La0.7Sr0.3MnO3 powders decreased first and increased then with the sintering temperatureʹs increase from 1273 K to 1523 K, and the lowest infrared emissivity was obtained when calcined at 1473 K. The trend of the variation of the infrared normal emissivity with sintering temperatureʹs increase was opposite to that of crystallite size and similar to that of resistivity.