Single cubic phase scandia-stabilized zirconia

Abstract

ZrO2:10 mol% Sc2O3 was mixed with MnO2 to evaluate its effect on cubic phase stabilization, oxide ion conductivity and aging at 600oC. Pressed ceramic pellets of zirconia stabilized with 10 mol% scandia with addition of 1.0, 2.0 and 2.5 mol% MnO2 were sintered at 1500°C/2 h. In situ high temperature X-ray diffraction data were collected to follow the rhombohedral-to-cubic transition. Polished and thermally etched surfaces of the sintered pellets were observed in scanning electron microscope. Impedance spectroscopy measurements were carried out. The single cubic structure is achieved for the specimen with 2 mol% MnO2 nominal addition. The electrical conductivity of this specimen was monitored at 600oC for 100 days. The ionic conductivity value remained constant, suggesting its use as solid electrolyte in SOFCs operating at that temperature.