Conductivity of ScSZ Ceramics in Vicinity of Polymorphic Phase Transitions

• Published in: ECS transactions Vol. 91; no. 1; pp. 1185 - 1192
• Main Authors: Barbashov, Vladimir I., Chaika, Eduard V.
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 10.07.2019
• ISSN: 1938-5862; 1938-6737; 1938-6737; 1938-5862
• DOI: 10.1149/09101.1185ecst

The effect of phase composition on ionic conductivity behavior in scandia-stabilized zirconia ceramics with various scandia concentrations during heating was studied. It was found that the homogeneous single-phase (cubic) ceramics reveals no hysteresis or kinks in Arrhenius plots (log σT versus 1/T) indicating on polymorphic transitions in course of heating within temperature range under study (523 to 823 K). Unlike the homogeneous material, two-phase ceramics demonstrates a conductivity jump in the low temperature range (600-630 K) of Arrhenius plot, which grows with increase in scandia concentration or decrease in grain size and corresponding rise in rhombohedral phase β content at room temperature. It is shown that this effect can be caused by intragrain crystal structure ordering under mechanical stresses arising in rhombohedral phase containing ceramics.