Tailoring charge transport in BaTiO3 crystals through dislocation engineering

Dislocations in oxide ceramics significantly influence their physical properties by creating substantial local strain fields, new electronic states, and space-charge layers. In this study, we investigated the effects of mechanically introduced dislocations on the electrical conductivity of BaTiO₃ single crystals. High-temperature plastic deformation was employed to introduce a high dislocation density with a {100}〈100〉 slip system. Impedance measurements revealed a significant anisotropy in the conductivity due to the presence of oriented dislocation structures. The crystals with dislocation lines aligned parallel to the measurement axis ([001] crystallographic direction) exhibited 16-fold higher conductivity compared to those measured across the dislocations. Compared to the pristine crystals, this means an increase in conductivity when the measurements were carried out parallel to dislocation lines and a decrease in perpendicular measurements. Our study demonstrates that not only ferroelectric properties but also charge transport can be modified by dislocation introduction in BaTiO₃.