Dislocation-Mediated Conductivity in Oxides: Progress, Challenges, and Opportunities.

Dislocations in ionic solids are topological extended defects that modulate composition, strain, and charge over multiple length scales. As such, they provide an extra degree of freedom to tailor ionic and electronic transport beyond limits inherent in bulk doping. Heterogeneity of transport paths as well as the ability to dynamically reconfigure structure and properties through multiple stimuli lend dislocations to particular potential applications including memory, switching, non-Ohmic electronics, capacitive charge storage, and single-atom catalysis. However, isolating, understanding, and predicting causes of modified transport behavior remain a challenge. In this Perspective, we first review existing reports of dislocation-modified transport behavior in oxides, as well as synthetic strategies and multiscale characterization routes to uncover processing-structure-property relationships. We outline a vision for future research, suggesting outstanding questions, tasks, and opportunities. Advances in this field will require highly interdisciplinary, convergent computational-experimental approaches, covering orders of magnitude in length scale, and spanning fields from microscopy and machine learning to electro-chemo-mechanics and point defect chemistry to transport-by-design and advanced manufacturing.