|About this Abstract
||MS&T22: Materials Science & Technology
||Dislocations in Ceramics: Processing, Structure, Mechanics, and Functionality
||Effects of Light Illumination on the Dislocation-mediated Plasticity in Single-crystalline ZnO
||Yan Li, Xufei Fang, Eita Tochigi, Yu Oshima, Katsuyuki Matsunaga, Atsutomo Nakamura
|On-Site Speaker (Planned)
Dislocation-mediated plasticity in ceramics and oxides has attracted increasing research interest due to the promising mechanical and functional properties tuned by dislocations. In this work, we investigated the effects of light illumination on the dislocation-mediated plasticity in single-crystalline ZnO by using photoindentation technique. Nanoindentation tests were conducted both in darkness and in light. From the load-depth curves, evident pop-in events were observed. The maximum shear stresses at pop-in were found to be about the theoretical shear strength regardless of light conditions, indicating homogeneous dislocation nucleation without the assistance of pre-existing defect at pop-in. The average values of maximum shear stresses were slightly larger in light than in darkness, exhibiting a ‘photo-hardening’ effect in ZnO. Furthermore, the suppression of dislocation behavior by light was validated by combining with TEM observations.