Fluorite structure oxides include cubic-stabilized ZrO2, HfO2, ThO2, UO2, and some rare-earth compositions. Many rare-earth oxides also form cubic bixbyite (Ln2O3) structures. These materials are some of the most refractory oxides known. The optical and thermomechanical properties of fluorite structured oxides and rare-earth bixbyites are reviewed. Existing data on transmittance in the visible and infrared is summarized and compared with theoretical predictions from density functional theory and other physics-based models. Properties such as thermal conductivity, thermal expansion, melting point, modulus, hardness, refractive index, dielectric constant, thermochemical stability, and the trade-offs between these properties and optical properties are also discussed. New results for optical and thermomechanical properties for selected bixbyite and fluorite compositions will be presented, compared with existing data, and with model predictions.
|