About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Advanced Materials for Energy Conversion and Storage 2023
|
Presentation Title |
D-14: Surface Oxidation of MNiSn (M=Ti, Zr, Hf) Half-Heusler Alloys |
Author(s) |
Oshrat Appel, Shai Cohen , Ofer Beeri, Yaniv Gelbstein, Shimon Zalkind |
On-Site Speaker (Planned) |
Oshrat Appel |
Abstract Scope |
Half-Heusler semiconductors have a very high potential as
thermoelectric materials in waste heat recovery devices at elevated temperatures. It is crucial to consider the environmental stability of the alloys at working conditions and therefore it is required to characterize their oxidation behavior. AES and XPS techniques were utilized to study the surface composition and the oxidation of the MNiSn (M=Ti, Zr, Hf) alloys by oxygen and water vapor at RT and 1000K. During heating in vacuum, Sn segregated to the surface, forming a sub-nanometer overlayer on the surface. Exposing the alloys to oxygen at RT and at 1000K has caused the formation of Ti, Zr and Hf oxides. It was found that HfNiSn is more susceptible to water vapor, while the oxidation of TiNiSn was more severe by oxygen. The oxidation of the MNiSn alloys implies that appropriate sealing of the thermoelectric devices is necessary in order to protect them. |
Proceedings Inclusion? |
Planned: |
Keywords |
Energy Conversion and Storage, |