Crystal structure,microstructure,thermal expansion and electrical conductivity of CeO 2 –ZrO 2 solid solution

Abstract

CeO₂–ZrO₂ solid solution was synthesised by mechanical activation solid-state chemical reaction method and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal dilatometer, Hebb–Wagner method and DC van der Pauw method. The effects of CeO₂ content on the crystal structure, microstructure, thermal expansion coefficient (TEC), electronic conductivity and total conductivity were investigated. XRD analysis showed that (25 and 75 mol-%) CeO₂–ZrO₂ solid solutions corresponded to tetragonal and cubic phase, and 50 mol-% CeO₂–ZrO₂ belonged to the mixture of tetragonal and cubic phases. SEM analysis showed that doping CeO₂ was helpful to the sinterability of CeO₂–ZrO₂ samples. The TECs increased from 13.27 × 10⁻⁶ to 14.72 × 10⁻⁶ K⁻¹ with increasing CeO₂ content. The electronic and total conductivities of 75 mol-% CeO₂–ZrO₂ were largest, reaching 1.02 × 10⁻⁴ S cm⁻¹ and 1.02 × 10⁻² S cm⁻¹ at 850°C, respectively.