In this study, Ca²⁺–Cr³⁺ co-doped LaAlO₃, a novel energy-saving material with significantly enhanced infrared emissivity, was synthesized by solid-state reaction. The experimental results demonstrated that 20 mol% Ca²⁺ and 10 mol% Cr³⁺-doped LaAlO₃, namely La_0.8Ca_0.2Al_0.9Cr_0.1O₃, had an infrared emissivity as high as 0.92 in the spectral region of 1–5 μm, which was 12 times higher than that of pure LaAlO₃. The first-principles electronic structure calculations revealed that the Ca²⁺–Cr³⁺ co-doping results in the occurrence of impurity energy levels in the forbidden band of LaAlO₃, which were mainly composed of the Cr 3d orbitals. Electrons partly occupied these impurity donor states and significantly reduced the energy bandgap, thus the infrared radiation property of LaAlO₃ was enhanced. This novel material with high infrared emissivity shows promising applications for energy-saving in the field of thermal process equipment.

Journal of the American Ceramic Society,2015

SEM images and photographs (insert) of the as-synthesized (a) LaAlO₃ and (b) La_0.8Ca_0.2Al_0.9Cr_0.1O₃