In-situ high-temperature micromechanical behavior of flash-sintered strontium titanate

Strontium titanate (SrTiO₃) is a versatile material with various applications but understanding its mechanical properties, especially in polycrystalline form prepared via field-assisted sintering methods, is limited. This study investigates the high-temperature mechanical properties of flash-sintered SrTiO₃ through in-situ microcompression tests comparing the behaviors near the positive and negative electrodes. Due to a significant irregularity in densification, the negative electrode exhibited superior fracture strength and strain across all temperatures when compared to its positive counterpart. Micropillars near the positive electrode contained multiple pre-existing pores that became crack initiation sites, and thus inducing catastrophic failure. Micropillars near the negative electrode exhibited prominent intergranular cracks accompanied by high-density dislocations in the vicinity of the fracture surfaces. This study elucidates the effect of flash sintering-induced defects on the mechanical properties of polycrystalline SrTiO₃ at various temperatures.