The influence of oxygen vacancy on the optical transmission of an yttria-magnesia nanocomposite

Highlights: → Fully dense Y2O3-MgO nanocomposite with grain size below 100 nm was successfully sintered using sol-gel processed nanopowder with a grain size below 30 nm. → The nanocomposite has an excellent transmission (∼80%) in the infrared range. → The optical transmission is reversible by changing annealing atmosphere from vacuum to air. → It is found that oxygen vacancy is responsible for the optical properties of the composite. -- A fully dense Y2O3-MgO nanocomposite with a grain size below 100 nm was successfully sintered using a sol-gel-processed nanopowder with a grain size below 30 nm. The nanocomposite has an excellent transmission (∼80%) in the infrared range. The nanocomposite is highly sensitive to the annealing environment in air or vacuum. The optical transmission is reversible by changing the annealing atmosphere from vacuum to air. Based on this combined with X-ray diffraction analysis, it is reasoned that oxygen vacancy is responsible for the optical properties of the composite.