Ba²⁺doping LaCoO₃to achieve dual-band low infrared emissivity at high-temperature

Low infrared emissivity materials are vital for suppressing thermal radiation. Nonetheless, precisely controlling infrared emissivity under high-temperature conditions remains a formidable technical challenge. This study tackles this issue through a novel Ba²⁺doping strategy, effectively modulating the infrared emissivity of LaCoO₃ perovskite materials. Remarkably, LaCoO₃ material doped with 50 mol% Ba²⁺exhibits excellent dual-band low infrared emissivity, achieving an infrared emissivity as low as 0.279 in the 3–5 μm band at 610 °C and 0.265 in the 8–14 μm band at 600 °C. By utilizing both experimental investigations and theoretical calculations, this study systematically elucidates the roles of the free carrier effect, lattice structure evolution, lattice-vibration-induced phonon effects, and surface plasmon effects on the dual-band infrared emissivity. This synergistic multi-mechanism approach surpasses the constraints of traditional single-factor regulation, offering a critical theoretical foundation and process guidance for designing high-temperature materials with low infrared emissivity.