Plastic Deformation of ⟨001⟩ Single-Crystal SrTiO3 by Compression at Room Temperature

The plastic deformation of (001) single-crystal SrTiO3 is investigated using compression along [001] at room temperature. A total plastic strain of similar to 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] (0 (1) over bar1) and [01 (1) over bar] (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] ((1) over bar 01) and [10 (1) over bar] (101), and [011] (0 (1) over bar1) and [0 (1) over bar1] (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 b = [(1) over bar 10] parallel to the load axis [001]. These dislocations are sessile, which eventually leads to sample fracture.