Enhanced near- and mid-infrared radiation property of MgCr2O4 by doping with Cu ions

作者：Wu, Qi; Sang, Shaobai^*; Wang, Guangyang; Wang, Qinghu; Huang, Liang; Zhu, Tianbin; Li, Yawei

来源：Ceramics International, 2023, 49(11): 17008-17017.

DOI：10.1016/j.ceramint.2023.02.063

• MgCr2O4
• Infrared emissivity
• Oxygen vacancies
• Band gap
• Industrial furnaces

MgCr2O4 is one of promising candidate to develop high near- and mid-infrared emissivity materials for industrial furnaces energy-saving, and its infrared emissivity property will be improved by doping Cu ions. The results show that Cu ions can be doped into the spinel lattice by solid-state sintering, and the single phase Mg1-xCuxCr2O4 (0.1. x. 0.4) radiation materials were prepared at 1200 degrees C. With the increase of the molar ratio of Cu ions from 0.1 to 0.4, their near- and mid-infrared emissivity all increase. The average infrared absorptivity of Mg0.6Cu0.4Cr2O4 is 0.81 in the wavelength range of 0.8-2.5 mu m, and the average infrared emissivity of Mg0.6Cu0.4Cr2O4 is 0.94 in the wavelength range of 2.5-13 mu m. Compared with MgCr2O4, the average infrared absorptivity in 0.8-2.5 mu m waveband and emissivity in 2.5-13 mu m waveband of Mg0.6Cu0.4Cr2O4 increased by 224% and 35% respectively. Cu ions in Mg1-xCuxCr2O4 had a mixed valence with Cu2+ and Cu+ valence state, and the forbidden bandwidth of MgCr2O4 decreased with doping Cu ions, which were responsible for the increase of near- and mid-infrared radiation of MgCr2O4 with doping Cu ions.