Ca2+-doped DyTa3O9: A novel rare-earth tantalate high emissivity material

This work aims to investigate the influence of Ca2+ doping on the infrared emission properties of DyTa3O9 ceramics. DyTa3O9 is considered a promising high-temperature thermal protection material due to its low thermal conductivity and good high-temperature stability. However, there is currently no research on the infrared radiation performance of such materials. We synthesized DyTa3O9 ceramics with different Ca2+ doping concentrations using the solid-phase reaction method and systematically investigated the effect of doping concentration on the infrared emissivity of DyTa3O9 ceramics. When Ca2+ is doped into the DyTa3O9 lattice, the original Dy elements are replaced by Ca, resulting in an increase in lattice constants and enhanced lattice distortion. The doping of Ca2+ introduces impurity energy levels, making it possible for some low-energy electron transitions, achieving an enhancement in infrared absorption and emission capabilities. When the Ca2+ doping concentration reaches 7.5% mol, the average infrared emissivity in the 3-5 mu m and 8-12 mu m ranges are 0.85 and 0.92, respectively, representing a 19.7% and 21% increase compared to DyTa3O9. This novel high-infrared-emissivity ceramic holds great potential for applications in high-temperature energy conservation and aerospace thermal protection.