Enhanced near-infrared transmission of ZnO-doped Y2O3–MgO nanocomposites with reduced light scattering due to decreased refractive index difference

Y2O3–MgO nanocomposites have received attention owing to their high optical and mechanical properties. However, the inevitable light scattering stemming from the refractive index difference between the two phases limits their applications in the near-infrared region. In this study, the grain boundary light scattering was reduced by doping ZnO into MgO. Y2O3–Mg1−xZnxO nanocomposites were fabricated by hot-press sintered nanopowders synthesized via the sol-gel combustion process. The addition of ZnO reduced the sintering temperature by almost 300 °C and reduced the average grain size by more than 50 nm. Transmittance of 75%–85% was maintained for all samples in the wavelength range of 2–6 µm. The near-infrared cut-on wavelength shifted from 1222 to 843 nm when the ZnO concentration was up to 25 mol%. This work demonstrates the potential of ZnO-doped Y2O3–MgO nanocomposites as infrared transparent ceramics over a wide infrared transmission range.