Preparation of environmentally friendly high‐emissivity Ca <sup>2+</sup> ‐Fe <sup>3+</sup> co‐doped LaAlO <sub>3</sub> ceramic
Qu Wang, Senwang Yan, Binbin Dong, Yifan Zhang, Qi Zhang, Penghui Du, Gang Wang
Abstract
Abstract Ca 2+ ‐Cr 3+ co‐doped LaAlO 3 is an excellent ceramic material with high emissivity; however, it is harmful to the environment because of the presence of Cr 3+ ions. In this study, Ca 2+ ‐Fe 3+ co‐doped LaAlO 3 ceramic materials were successfully prepared via a high‐temperature solid‐state reaction. The emissivity of Ca 2+ ‐Fe 3+ co‐doped LaAlO 3 was 0.91, which is approximately equal to that of Ca 2+ ‐Cr 3+ co‐doped LaAlO 3 . To compensate for the lack of data on the thermophysical properties of doped LaAlO 3 high‐emissivity ceramics, the thermal expansion coefficients and thermal conductivities of LaAlO 3 doped with Ca 2+ ‐Fe 3+ or Ca 2+ ‐Cr 3+ were investigated. The thermal conductivities of La 0.9 Ca 0.1 Al 0.9 Fe 0.1 O 3 and La 0.9 Ca 0.1 Al 0.9 Cr 0.1 O 3 at 1200°C were 3.802 and 3.707 W·m −1 ·K −1 , respectively. The thermal expansion coefficients of La 0.9 Ca 0.1 Al 0.9 Fe 0.1 O 3 and La 0.9 Ca 0.1 Al 0.9 Cr 0.1 O 3 at 1200°C were 11.49×10 −6 and 11.41×10 −6 K −1 , respectively. These results indicate that Ca 2+ ‐Fe 3+ co‐doped LaAlO 3 exhibits great potential as a new generation of environmentally friendly near‐infrared radiating materials in the field of energy efficiency.