  We report room-temperature bulk plasticity mediated by dislocations in
single-crystal cubic KTaO3, contrasting the conventional knowledge that
single-crystal KTaO3 is susceptible to brittle cleavage. A mechanics-based
combinatorial experimental approach using cyclic Brinell indentation,
scratching, and uniaxial bulk compression consistently demonstrates
room-temperature dislocation plasticity in KTaO3 from the mesoscale to the
macroscale. This approach also delivers tunable dislocation densities and
plastic zone sizes. Scanning transmission electron microscopy analysis
underpins the activated slip system to be <110>{1-10}. Given the growing
significance of KTaO3 as an emerging electronic oxide and the increasing
interest in dislocations for tuning physical properties of oxides, our findings
are expected to trigger synergistic research interest in KTaO3 with
dislocations.
