Surprising results of a study on the plasticity in strontium titanate

Oxides such as SrTiO3 are expected to fail via brittle fracture at low temperatures. Surprisingly, in the present study, SrTiO3 single crystals could be plastically deformed in compression in two temperature ranges: from 78 K to similar to 1050 K and from 1500 K to 1800 K. SrTiO3 was brittle at temperatures between these two ranges (similar to 1050-1500 K). This phenomenon of a ductile-brittle-ductile transition, together with microstructural investigations, suggests that the role of dislocations in the plasticity of ceramics must be reconsidered.