Ionic Conductivity of Scandia Stabilized Zirconia and Alumina Composites

Abstract

This paper analyses the conductivity data of composite electrolytes in the 6ScSZ-AI₂O₃ system. The system provides a heterogeneous solid electrolyte in which the grain conductivity remains unaffected, whereas the grain boundary conductivity increases up to 20 wt% of AI₂O₃. The bulk conductivity, which includes contributions from both grain and grain boundary conductivity, therefore shows an enhancement with AI₂O₃ addition. The enhancement is explained on the basis of space charge formation at the ScSZ-AI₂O₃ boundaries. The conductivity of these composite specimens decreases when the AI₂O₃ concentration is increased to 30 wt%.

Keywords:

• Ionic conductivity
• Stabilized zirconia
• Composites
• Grain boundary
• Space charge