Dielectric properties of plastically deformed strontium titanate

Recent studies demonstrate the promise of plastic deformation as a tool to manipulate the electronic properties of quantum materials [1]. Here we present the results of 4-terminal capacitance measurements of insulating, plastically deformed strontium titanate, SrTiO₃. Significant differences compared to undeformed samples are clearly seen in the temperature dependence of the permittivity, where we observe evidence for a first-order phase transition close to ambient temperature. The transition is likely related to local ferroelectricity around dislocation structures, the existence of which was uncovered previously [1]. We also find a strong influence of an external magnetic fields on the transition, which points to a large magneto-electrical coupling that could be important for applications.

[1] S. Hameed et al., Nat. Mater. 21, 54 (2022)