Infrared‐Transparent Y 2 O 3 –MgO Nanocomposites Using Sol–Gel Combustion Synthesized Powder

Y 2 O 3 –MgO composite nanopowder with a volume ratio of 50:50 was synthesized using a sol–gel combustion process. X‐ray diffraction analysis of the as‐synthesized nanopowder shows phase pure Y 2 O 3 and MgO with a cubic crystal structure and crystalline size ∼15 nm. The fully dense Y 2 O 3 –MgO nanocomposites were prepared by pressureless sintering the composite nanopowder at 1400°C for 2 h, followed by hot isostatic pressing at 1350°C for 1 h and postsinter annealing at 1000°C for 10 h. The Y 2 O 3 –MgO nanocomposite exhibit excellent infrared transmittance (62%–80%) over 3–7 μm infrared wavelength ranges with an average hardness of 10.6 GPa.