About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Atomistic Structure and Dynamics of Aliovalent Dopants in Oxide Grain Boundaries |
| Author(s) |
Toshihiro Futazuka, Ryo Ishikawa, Tatsuya Yokoi, Katsuyuki Matsunaga, Naoya Shibata, Yuichi Ikuhara |
| On-Site Speaker (Planned) |
Toshihiro Futazuka |
| Abstract Scope |
Impurity doping is a major strategy for tailoring the properties of ceramics. Dopants usually segregate to the grain boundaries (GBs) in ceramics and typically substitute for specific cation sites in the GB, as has been characterized for isovalent dopants. However, when an aliovalent dopant is introduced to the GB, charge-compensating dopants or defects must be introduced, which significantly influences the structure and dynamics of GBs. Due to the complicated interaction between aliovalent dopants or defects in the GBs, it has been difficult to elucidate the behavior of aliovalent doping in the GB. In this study, we characterize the effect of aliovalent dopants on the structure, dynamics, and energetics of GBs by combining atomic-resolution scanning transmission electron microscopy and theoretical calculations. We discuss the structural transformation of the α-Al2O3 GB induced by the co-segregation of Ca2+ and Si4+, and the dynamics of Hf4+ and Al vacancies along the α-Al2O3 GB. |