About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Ceramic Materials and Processing
|
| Presentation Title |
Defect-mediated Room-temperature Deformability in NbNx |
| Author(s) |
Yang Chen, Ke Xu, Xuanyu Sheng, Chang Liu, Chao Shen, Debargha Paul, Stephen Hellberg, Yifan Zhang, Benson Tsai, Huan Li, Shiyu Zhou, Jialong Huang, Yinghang Liu, Changxin Han, Noam Bernstein, Edwin Garcia, Haiyan Wang, Xinghang Zhang, |
| On-Site Speaker (Planned) |
Yang Chen |
| Abstract Scope |
Nitrogen vacancies play a critical role in controlling the microstructure and deformation behavior of transition-metal nitrides. NbNx thin films with various nitrogen contents (x = 0.72, 0.91, and 0.94) were synthesized by reactive magnetron sputtering. Microstructural characterization revealed a progressive transition from coarse, textured columnar grains at high nitrogen content to a fine-grained microstructure with stacking faults in the nitrogen vacancy-rich NbN0.72. In situ micropillar compression showed that the nitrogen vacancy-rich films displayed an extended room-temperature strain of 6.4 % while maintaining load-bearing capacity, whereas the near-stoichiometric films exhibited limited plasticity. Post-deformation TEM and PED revealed that the enhanced deformability of NbN0.72 is driven by a synergistic mechanism combining extensive stacking-fault-mediated shear, widespread lattice rotation, and dynamic grain subdivision. First-principles calculations predict nitrogen preferentially segregates towards stacking faults under nitrogen-deficient conditions. These findings demonstrate that vacancy engineering provides an effective pathway to tailor defect structures and deformation mechanisms in NbNx. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Ceramics, Characterization, Thin Films and Interfaces |