Non-Arrhenius behavior of grain growth in strontium titanate: New evidence for a structural transition of grain boundaries

The grain growth constant of strontium titanate shows a transition to slower grain growth in the temperature range between 1300 °C and 1390 °C. The current study refines recently published grain growth data. This grain growth anomaly is coupled with the occurrence of bimodal microstructures and exaggerated grain growth. The results give evidence for the coexistence of two different grain boundary types, a fast low temperature type and a slow high temperature type. Their transition seems to cause the grain growth anomaly.