| Abstract Scope |
Defect chemistry for point defect engineering is widely used for tuning the properties of functional oxides. Most recently, dislocations (line defects) in ceramics are gaining new research momentum to provide a new perspective for (re)thinking functional ceramics engineering. Due to the ionic bonding in oxides, the point defects and dislocations can carry charges. A fundamental understanding of (charged) point defect-dislocation interactions in ceramics remains largely unexplored in functional oxides. Here, we use a scale-bridging deformation approach including nanoindentation (nano-/microscale), Brinell indentation (mesoscale), and uniaxial bulk compression (macroscale) to investigate the impact of oxygen vacancies, donor and acceptor dopants (Nb and Fe, respectively), on the room-temperature dislocation plasticity in SrTiO3. We find oxygen vacancies play a dual role in facilitating dislocation nucleation but suppressing dislocation motion, while Nb-doping (0.5 wt%) consistently suppresses dislocation nucleation, multiplication, and motion. These insights reveal the importance of defect chemistry on dislocation plasticity in functional oxides. |