Fracture Toughness and Ionic Conductivity of Niobium Co-doped Yttria Stabilized Cubic Zirconia

Yttria stabilized cubic zirconia possess high oxygen ionic conductivity and chemical stability but low fracture toughness due to premature fracture due to thermal and mechanical stresses. Addition of 1.5mol% Nb₂O₅ to yttria stabilized cubic zirconia increases the fracture toughness by controlling grain growth in the sintered samples. Ionic conductivity studies showed that grain boundary resistance was predominant at low and high values of Nb₂O₅ and grain boundary conductivity increased with increase in temperature for 1.5mol% Nb₂O₅ addition.