Plastic Deformation of 〈001〉 Single‐Crystal SrTiO3 by Compression at Room Temperature

Abstract

The plastic deformation of (001) single‐crystal SrTiO3 is investigated using compression along [001] at room temperature. A total plastic strain of ∼19% ± 2% is consistently obtained. The stress–strain curve exhibiting four work‐hardening stages are describable using the stage 0 of axis rotation, the stage I “easy glide,” the stage II multiple slip and the wall‐and‐cell structure, and the stage III work softening and dynamic recovery before sample fracture takes place. It is revealed by analyzing the microstructure for each work‐hardening stage that the plastic deformation of single‐crystal SrTiO3 closely resembles that of metals. The primary slip systems of [011] and (011) predominate in stage I where plastic deformation occurs by the migration of kink pairs in collinear partial dislocations. The activation of multiple slips including [101] and (101), and [011] and (011) in stage II produces the cell‐and‐wall structure which is also characteristic of plastically deformed metals. In stage III with decreasing work‐hardening rate, the bow‐out dislocation interaction from opposite walls results in annihilation. The reaction between dislocations from adjacent walls produces the resultant dislocations with parallel to the load axis [001]. These dislocations are sessile, which eventually leads to sample fracture.