Dy2O3–MgO composite ceramics: Fabrication and properties

An IR-transparent magneto-optical Dy2O3–MgO compositeceramics was fabricated by vacuum hot pressing of glycine-nitrate self-propagating high-temperature synthesized nanopowders. Composites significantly outperform dysprosium sesquioxide ceramics in terms of thermal conductivity and mechanical properties.The HV1 microhardness of the Dy2O3–MgO composite is 9.9 GPa and the fracture toughnessKIC, calculated by the Palmquist method, is 1.7 MPa m½. The thermal conductivity of the composite was measured in the range of 50–300 K and is 10.6 W/(m K) at room temperature. The transmittance of 1.5 mm thick Dy2O3–MgO sample is about 70 % in the wavelength range ∼2.1–2.2 μm and more than 80 % in the range ∼3.6–6.5 μm, which is close to the theoretical value for dysprosium sesquioxide.The value of Verdet constant of Dy2O3–MgO composite ceramics is 7.0 ± 0.3 rad/(T∙m)at 1940 nm.