AC impedance study of Ni, Fe, Cu, Mn doped ceria stabilized zirconia ceramics

Doped zirconia has been used in electronic applications in the cubic crysta lline phase. Ceria-stabilized tetragonal zirconia presents high toughness a nd can also be applied as solid electrolytes. The tetragonal phase of zirco nia can be stabilized at room temperature with ceria in a broad range of co mposition. However, CeO2-ZrO2 has low sinterability. so it is important to investigate the effect of sintering dopants. In this study the effect of ir on, copper. manganese and nickel was investigated. The dopants such as iron and copper lowered the sintering temperature from 1600 degreesC down to 14 50 degreesC, with a percentage of tetragonal phase retained at room tempera ture higher than 98% and also with an increase of the electrical conductivi ty. The electrical conductivity was measured using impedance spectroscopy. The grain boundary contribution was determined and the activation energy as sociated with the ionic conduction was 1.04 eV. The dopants can also promot e a grain boundary cleanliness verified by blocking effect measurement. (C) 2001 Elsevier Science Ltd. All rights reserved.