Abstract
Incorporating Raman spectroscopy with transverse lift-out specimens is demonstrated to effectively characterize depth-dependent ion-irradiation damage in nuclear ceramics, such as SiC/SiC composites irradiated up to 1, 10 and 50 displacements per atom (dpa) at 350 °C using 10 MeV Au ions. Raman spectroscopy reveals irradiation-induced structural disorder saturation in both SiC-fiber and SiC-matrix at doses as low as 1 dpa, despite vastly different microstructures, inferred from similar longitudinal optical (LO) and transverse optical (TO) phonon peak shifts. Diamond (D) and graphitic (G) peaks from SiC-fibers disappear under irradiation, revealing irradiation-induced carbon packet loss. The irradiation-induced carbon packet loss is also verified by conducting TEM on same FIB foils used for Raman spectroscopy. In a previous study, the irradiation-induced SiC-fiber shrinkage is known to occur due to carbon packet loss in fibers.
| Original language | English |
|---|---|
| Article number | 151778 |
| Journal | Journal of Nuclear Materials |
| Volume | 526 |
| DOIs | |
| State | Published - Dec 1 2019 |
Funding
This work was supported in part by the U.S. Department of Energy, Office of Nuclear Energy's Nuclear Energy University Program under grant DE-NE0008577 .
Keywords
- Carbon loss
- Irradiation damage
- Raman spectroscopy
- SiC/SiC composites
- Structural disorder