Stability of the structural and electrical properties of solid electrolytes in the ZrO2 – Sc2O3 system

The stability of the structural and electrical properties of solid electrolytes in the ZrO₂ – Sc₂O₃ system (8-11 mol % of SC2O3) obtained by the solid state technique was investigated.
By means of X-ray analysis and Raman spectroscopy it was established that the relative content of rombohedric phase in the specimens' structure decreases in the process of cyclic stability tests at 900°C during 400 hours with an appropriate increase of the cubic phase content. On an increased duration of tests the tetragonal phase with a low stabilizing oxide content was fixed. The latter phase is metastable and possibly partially decomposes with the appearance of a monoclinic phase, whose influence is more remarkable at lower temperatures. As a result of these processes, the conductivity of the solid electrolytes decreases.
The stability of the solid electrolyte properties increases with the Sc₂O₃ content.