Electrical conductivity of sol–gel derived yttria-stabilized zirconia

A 3 mol% Y₂O₃ zirconia stabilized powder has been synthesized by destabilization of an aqueous zirconia sol prepared by the alkoxide hydrolysis method. The powder calcined at 500°C is ultrafine with tetragonal crystallites of about 8 nm, slightly agglomerated and with a narrow pore size distribution having an average pore size of 5.2 nm. Zirconia ceramics with density higher than 92%TD and grain size on the order of 100 nm have been obtained by uniaxial pressing at 500 MPa and vacuum sintering at 1000°C. Electrical conductivity of sintered samples, evaluated by complex impedance spectroscopy measurements, indicated that the zirconia stabilized with 3 mol% Y₂O₃ can potentially be used as an oxygen semipermeable dense membrane, but only at a relatively high temperature.