| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior Related to Interface Physics IV
|
| Presentation Title |
Scale Bridging Characterization of Grain Boundary Engineered Thermoelectric Materials |
| Author(s) |
Christina Scheu, Ruben Bueno Villoro, Chanwon Jung, Dominique Mattlat, Duncan Zavanelli, Jeff Snyder |
| On-Site Speaker (Planned) |
Christina Scheu |
| Abstract Scope |
Thermoelectric materials can contribute to the renewable energy sector by generating electricity from waste heat. They should possess a high electrical conductivity, low thermal conductivity and good mechanical strength. Grain boundaries can scatter phonons efficiently but often reduce electrical conductivity. In order to prevent this, grain boundary engineering is required. In the present talk, a scale bridging methodology is presented to analyze Ti(Co,Fe)Sb Half-Heusler thermoelectric material from the micrometer to the sub-nanometer scale including scanning transmission electron microscopy (STEM) and atom probe tomography. The results show that random grain orientation occurs with grain sizes in the order of 260 nm to 5 µm depending on the processing conditions. The Half-Heusler alloy possesses significant Fe segregation and Co depletion at the grain boundaries as revealed by atom probe tomography and STEM/EDS. Atomic column resolved STEM images reveal that a grain boundary phase (“complexion”) forms which acts as fast charge carrier pathway. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Energy Conversion and Storage, Thin Films and Interfaces |