Ionic conductivity of eutectic mullite-zirconia fibres

Mullite-stabilized zirconia fibres were synthesized by the laser floating zone (LFZ) method. Fibres grown at 100 mm/h have fine-interpenetrating mullite-zirconia eutectic grains surrounded by an amorphous phase rich in Al, Y and Si. The crystalline phases identified by XRD are mullite with an orthorhombic crystal structure and zirconia polymorphs, occurring in the tetragonal and transformable monoclinic forms. The activation energy for the conductivity of these composites determined from Arrhenius plots between 600°C and 800°C is 1.16 eV.