4 January 2026 - New publication in Journal of American Ceramic Society
Dislocation interaction with a tilt low-angle grain boundary in bi-crystal SrTiO3
The study investigates how dislocations interact with a 4° low-angle tilt grain boundary (LAGB) in bi-crystal SrTiO₃ at room temperature. Understanding such interactions is essential for developing dislocation-engineered ceramics, since grain boundaries often block slip and promote cracking. Cyclic Brinell indentation is used to generate large, crack-free plastic zones, enabling mesoscale observation of dislocation–boundary processes in bulk material.
Combining dislocation etch-pit imaging with transmission electron microscopy, we identify dislocation pile-ups, storage within the boundary, and transmission events. Two dominant slip systems—[011](0 1 1̄) and [101](1 0 1̄)—are documented crossing or interacting with the LAGB. In some regions, dislocations transmit directly; in others, pile-ups raise local stress and appear to nucleate new slip in the neighboring grain rather than transferring existing dislocations across the boundary. The work shows that even a simple LAGB behaves in a complex way, acting simultaneously as barrier, storage site, and source.
The mesoscale results extend earlier nanoscale in-situ TEM findings, demonstrating that slip transmission across LAGBs can occur in bulk while crack formation is suppressed. We also highlight that geometric criteria alone cannot predict transmission: the local atomic structure and Burgers-vector compatibility at the boundary are crucial.
Overall, we show that transmission electron microscopy combined to etch pits observations represents a powerful approach for probing dislocation–grain-boundary interactions in ceramics at technologically relevant scales, informing future strategies for toughening and functional tuning via dislocation engineering.
To learn more:
K. Ding, A. Zelenika, A. Nakamura, P. Cordier & X. Fang (2026) Dislocation interaction with a tilt low-angle grain boundary in bi-crystal SrTiO3. Journal of the American Ceramic Society, 109, e70492. https://doi.org/10.1111/jace.70492