Effect of grain size on electrical properties of scandia-stabilized zirconia

Abstract

10 mol % Sc₂O₃-stabilized ZrO₂ (10ScSZ) was sintered by several processes including spark plasma sintering, milliwave sintering and conventional sintering. The electrical conductivity of the sintered 10ScSZ samples was obtained by AC impedance spectra, and compared with grain size and the crystal phase. As average grain size decreased, the electrical conductivities decreased and increased at temperatures higher and lower than the phase transition point, respectively. These trends suggested that the fraction of a low conductivity rhombohedral phase increases with increasing grain size at a temperature lower than the phase transition point, and that the total thickness of the grain boundary affects the electrical conductivity at a temperature higher than the phase transition point.