| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Atom Probe Tomography for Advanced Characterization of Metals, Minerals and Materials III
|
| Presentation Title |
APT-based Stoichiometry Measurements of Single Crystal ThO2 |
| Author(s) |
Amrita Sen, Mukesh Bachhav, Janelle Wharry |
| On-Site Speaker (Planned) |
Amrita Sen |
| Abstract Scope |
The objective of this study is to obtain accurate stoichiometric measurements of single crystal ThO2 using Laser-Atom Probe Tomography (APT). Compositional accuracy of insulators and metal-oxides materials by APT is known to be influenced by operating parameters such as laser energy, field condition, and base temperature. Systematic variation of these parameters reveals improved ThO2 stoichiometry with increasing laser energy and decreasing base temperature. However, interpretation of these results is not straightforward. As with other oxides, poor laser absorption due to low thermal conductivity of ThO2 results in non-uniform field evaporation behavior, introducing thermal effects into the obtained mass spectra. Generally, such thermal effects negatively impact compositional accuracy. However, ThO2 is distinct from other oxides in that improved stoichiometry is achieved from the thermally-affected mass spectra, compared to results from spectra with better mass resolution. The cause for this behavior, and its influence on interpretation of data will be discussed. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |