Mechanical tailoring of dislocation densities in SrTiO3 at room temperature

Dislocation-tuned functional properties such as electrical conductivity, thermal conductivity, and ferroelectric properties in oxides are attracting increasing research interest. A prerequisite for harvesting these functional properties in oxides requires successful introduction and control of dislocation density and arrangement without forming cracks, which is a great challenge due to their brittle nature. Here, we report a simple method to mechanically tailor the dislocation densities in single-crystal perovskite SrTiO3. By using a millimeter-sized Brinell indenter, dislocation densities from similar to 10(10) to similar to 10(13) m(-2) are achieved by increasing the number of indenting cycles. Depending on tip radius and indenting load, large and crack-free plastic zones over hundreds of micrometers are created. The dislocation multiplication mechanisms are discussed, and the work hardening in the plastic zone is evaluated by micro-hardness measurement as a function of dislocation density. This simple approach opens many new opportunities in the area of dislocation-tuned functional and mechanical studies.

Automated summary

A simple method is reported to mechanically tailor dislocation densities in single-crystal SrTiO3 by increasing the number of indenting cycles using a millimeter-sized Brinell indenter. This approach creates large and crack-free plastic zones over hundreds of micrometers, opening new opportunities in the area of dislocation-tuned functional and mechanical studies.