Effect of Sintering Conditions on the Microstructure and Electrochemical Properties of 6Scandia 1Ceria co-doped Zirconia (6Sc1CeZr)

Abstract

The current work studies the effect of sintering conditions on the densification behavior, microstructure, and electrochemical performance of 6 mol% Sc2O3, 1 mol% CeO2 co-doped ZrO2 (6Sc1CeZr) for solid-state electrolyte applications. The specimen's physical properties and electrochemical performance sintered at different temperatures ranging from 1000 {\deg}C to 1700 {\deg}C for 6 hours are examined through diffraction, microscopy, and Raman and electrochemical impedance spectroscopy. The activation energy and pre-exponential conductivity factor of the oxygen ions are calculated using a linear fit to the Arrhenius-type conductivity equation. We observe that samples sintered at 1500 {\deg}C for 6h show a lower c/a axial ratio for the tetragonal phase, highest relative density, and highest total conductivity among all samples investigated. The higher total conductivity is explained by the formation of a higher symmetric tetragonal phase and the simultaneous existence of the cubic and tetragonal phases (with higher symmetry), supported by the presence of the cerium ions partially replaced zirconium ions' sites.