Ca2+‐Doped LaCrO3: A Novel Energy‐Saving Material with High Infrared Emissivity

Abstract

The present study describes the successful synthesis of a Ca2+‐doped LaCrO3 ceramic with high infrared (IR) emissivity, which is important for high‐temperature applications for significant energy saving. It is demonstrated that 20 mol% Ca2+‐doped LaCrO3, i.e., La0.8Ca0.2CrO3, exhibited an IR emissivity as high as 0.95 in the spectral region of 3–5 μm, which was 33.8% higher than that of LaCrO3. By using La0.8Ca0.2CrO3 as IR radiation agent in surface coating of heating unit, the radiative heat transfer could be enhanced significantly. The mechanism of the high IR emissivity of La0.8Ca0.2CrO3 was attributed to the following aspects: Ca2+ doping introduced an impurity energy level of Cr4+ into LaCrO3 and increased the hole carrier concentration, enhancing both impurity absorption and hole carrier absorption in the IR region; moreover, the doping caused lattice distortion enhanced the lattice vibration absorption. This novel high IR emissivity ceramic shows a promising future in high‐temperature applications for the purpose of energy‐saving.