Oxygen ion conduction in ternary zirconia mixtures: Effect of SrO on MgSZ

• Published in: Solid state ionics 1990, Vol.40, p.947-951
• Main Authors: Poulsen, F.W., Bilde-Sørensen, J.B., Ghanbari-Ahari, K., Knab, G.G., Hartmanová, M.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Transport properties of condensed matter (nonelectronic)
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/0167-2738(90)90160-S

Magnesia stabilized zirconia (9, 13.5 and 17 mole% MgO) with and without 0.3 w/o strontia additions have been investigated by impedance spectroscopy and X-ray diffractometry. Sr addition has a significant influence on preserving the cubic form of zirconia and thus also in increasing the conductivity of MgSZ compared with the SrO free material. The 13.5 mole% MgSZ + 0.3 w/o SrO material has the highest conductivity of 0.069 S cm at 1000°C. Several impurity phases were found in the 17 mole% MgSZ samples by transmission electron microscopy. Grain boundary conductivity could not be resolved from the total conductivity for the MgSZ materials. 2 w/o CuO and 0.3 w/o Fe 2O 3 doped YSZ (15 mole% Y 2O 3) were also studied. For these materials bulk and grain boundary conductivity could be resolved from 250 to 916°C. The activation energies and preexponential terms of the Arrhenius expressions for the total conductivity of the eight different compositions surprisingly follow a common compensation law.