Preparation and mechanical properties of dense Ce0.8Gd0.2O2−δ ceramics

Nanocrystalline Ce0.8Gd0.2O2−δ powder has been prepared from a homogeneous precipitation system using hexamethylenetetramine as a precipitant. The powder characteristics, sinterability and mechanical properties have been examined. The powder calcined at 700–800 °C has an optimal sinterability, and can be sintered to nearly full density (>99.0% relative density) at a temperature as low as 1250 °C. Dense Ce0.8Gd0.2O2−δ ceramics (>97.0% relative density) with grain size range of ∼0.5–9.5 μm can be obtained by controlling sintering temperature and time. The ceramic with a mean grain size of ∼2.63 μm has a fracture toughness of ∼1.53±0.2 MPa m1/2; and no fracture toughness dependence of grain size (∼0.5–9.5 μm) has been found in this study for dense Ce0.8Gd0.2O2−δ ceramics.